Bonni's Principle

Bonni's Principle is a philosophical principle that states the fundamental conditions of existence not as a state, but as a process of prolonged resolution.

Existence cannot consist of a static state. In order to exist, an entity must necessarily resolve, simultaneously and in a prolonged manner:

1. a non-fixed state by means of a minimal and invariable set of constraints,
2. a dissipation mechanism for the part not absorbed by these constraints, sustained by that same set of constraints.

There is then a confusion of “physical reality” with its “mathematical description”.

This principle shifts the ontological question from substance to a regime of dynamic coherence. It offers a novel conceptual framework for thinking metaphysics and the conditions of reality together. We shall explore here its philosophical implications, from questions of time and chance to that of God.

Why another philosophy of existence?

The acknowledgement of insufficiency

The question of existence — why is there something rather than nothing? — runs through the history of thought without ever finding a satisfactory answer. From Aristotle to the present day, each era has produced its concepts: entelechy, substance, conatus, élan vital, Dasein. Yet a fracture persists between metaphysics, which questions the meaning of being, and physics, which describes its manifestations.

The anthropic principle, popular in contemporary cosmology, illustrates this impasse well. In its weak form, it merely notes that the universe must possess certain properties for us to be able to observe it. In its strong form, it suggests that the universe is necessarily organised to produce life. But neither version really explains why the fundamental constants are tuned with extraordinary precision. Fine‑tuning is observed, but not explained.

At the same time, the great philosophies of existence struggle to provide an operational framework. Aristotelian entelechy describes the passage from potentiality to actuality without ever specifying the mechanisms of this transition. Spinozist conatus asserts that each thing strives to persevere in its being, but does not say why these efforts take the physical forms we observe. Bergson’s élan vital, powerful for thinking creation and duration, does not allow us to deduce the laws of medicine or quantum mechanics. Heidegger’s philosophy of being, masterful on the existential plane, remains silent in the face of the equations of physics. And this is not for lack of genius: it is because these systems describe existence as a state, substance or essence, but do not conceive it as a process capable of mechanically engendering its own conditions.

This limitation is not, moreover, the preserve of the West. In the ancient traditions of Asia, Buddhism develops the idea of anicca (impermanence) and of becoming as the fundamental nature of reality, close to the intuition of perpetual flux. Taoism evokes the Tao as a spontaneous and creative process, the source of all becoming. Yet these insights, however profound, have never been translated into systems capable of predicting or explaining the fundamental structures of matter. They describe being as becoming magnificently, but they do not say why this becoming takes precisely these mathematical forms.

The hypothesis of an inversion

Bonni's Principle proposes a radical inversion. Instead of starting from being in order to describe its properties, it starts from the process in order to deduce its conditions. Existence is not a state, a substance or an essence — it is a regime of resolution, a structured becoming subject to constraints and sustained by continuous dissipation.

What distinguishes this principle is, first of all, its minimal character. It does not postulate matter, space, time or consciousness as primitives, but a relational process under constraints. It is then its dynamic dimension: existence is not the attainment of an equilibrium, but the maintenance of a productive disequilibrium.

Stakes

Having presented and explained the statement of the Principle, we shall now examine the place of Bonni's Principle in the history of thought — from classical Greek philosophy to Eastern wisdoms, from modern metaphysics to contemporary science.

We shall proceed in three stages. First, we shall situate this principle in relation to the great philosophical and spiritual traditions: Aristotle’s entelechy, Spinoza’s conatus, Bergson’s becoming, but also Buddhist impermanence and Taoist flux. Next, we shall examine its relevance to established scientific theories, questioning its capacity to shed light on fine‑tuning, the arrow of time and the emergence of complexity.

Finally, we shall address the questions the Principle raises: what about time, if existence is a process of resolution? What about chance, if the constraints are invariable? What about evolution, God, finality? Bonni's Principle does not claim to provide the definitive answer. It proposes a displacement: from the quest for laws governing objects to the study of the conditions of possibility of a stable regime of existence.

What the Principle says

“Existence cannot consist of a static state.”

This initial statement does not constitute a mere observation, but a principled exclusion. It forbids defining existence as a fixed datum or as the persistence of a state. To exist does not mean to be given, but to maintain oneself. It thus introduces a first constraint: any existence implies a dynamic.

“In order to exist, an entity must necessarily resolve simultaneously and in a prolonged manner…”

The term resolution is central here. It does not designate an achieved state, but an ongoing process. An entity does not exist because it has resolved a configuration, but because it is engaged in a resolution that does not stop.

Two precisions immediately determine its scope:

• simultaneously: the conditions of this resolution are not successive but co‑present;
• in a prolonged manner: existence is not a punctual event, but the persistence of this regime.

Existence thus appears as an operative maintenance, and not as an acquired property.

“1. …a non‑fixed state by means of a minimal and invariable set of constraints”

This first condition introduces a structuring of the process. The state must be non‑fixed, which excludes any definitive stabilisation. But this non‑fixity is not left to indetermination: it is framed by a set of constraints.

The minimal character means that these constraints constitute the smallest sufficient set to enable this maintenance. Their invariable character indicates that they do not depend on the evolution of the system: they define its framework, not its content.

It follows that existence is neither fixity nor free variation, but a constrained variation.

“2. …a dissipation mechanism for the part not absorbed by these constraints”

This second condition is not a consequence of the first, but a distinct requirement. The principle does not assert that the constraints are incapable of absorbing all variations; it imposes that a mechanism exists which does not fully absorb their effects.

Dissipation thus introduces a second regime in the process: alongside integration by the constraints, it ensures the evacuation of what is not retained.

These two regimes — integration and dissipation — are not interchangeable. Taken in isolation, each leads to the disappearance of the process:

• total integration would lead to complete stabilisation, incompatible with the requirement of non‑fixity;
• dissipation without structuring would prevent any maintenance, in the absence of a constraining framework.

The principle therefore imposes their coexistence.

“…sustained by that same set of constraints.”

This point is decisive. The principle does not juxtapose two independent mechanisms: it requires that they be governed by the same set of constraints.

It follows that integration and dissipation are not externally opposed, but are two expressions of a single framework. Any variation is simultaneously subject to what structures it and to what evacuates a part of it.

This double constraint does not define a state of equilibrium in the classical sense, but a specific mode of functioning. The system is prevented from stabilising completely, while being prevented from dissolving.

Existence then takes the form of a continuous critical equilibrium: a regime in which the process maintains itself precisely because it is constrained never to reach either complete stability or total disorganisation.

This point constitutes the heart of Bonni's Principle. It is neither constraint alone nor dissipation alone that define existence, but their necessary articulation within a single system.

“There is then a confusion of ‘physical reality’ with its ‘mathematical description’.”

This statement can only be understood in the light of what precedes.

If a process is entirely defined by a minimal and invariable set of constraints, and if this set does not depend on any underlying level, then its formalisation does not constitute an external description. It directly expresses what is.

However, this coincidence does not hold for the particular systems that can be isolated. An entity such as a moving ball, or even a living organism, can be described as a process of resolution under constraints accompanied by dissipation. But this description rests on an abstraction: these systems depend on conditions that are not included in them — gravity, structure of space, fundamental interactions.

The error then consists in artificially isolating a local process and attributing to it an autonomy that it does not possess. Its mathematical description does not coincide with its reality, because it does not capture the whole set of conditions that make it possible.

It is only by considering a level where no external condition is presupposed — a level where the constraints constitute the entirety of the real — that the distinction between description and reality can disappear.

Bonni's Principle therefore applies rigorously only to this fundamental level. The objects, beings and structures we observe are not autonomous existences, but local resolutions of a global process of continuous resolution.

Situation of Bonni's Principle in the history of thought

The philosophy of existence has long been built around a fundamental tension: should being be thought as that which remains, or as that which becomes? Since the origins of Western thought, a dominant tendency has consisted in seeking, behind change, a principle of stability — a substance, a form, an essence — that would guarantee the identity of things through time.

Bonni's Principle breaks with this orientation. It does not seek what persists beneath change, but what makes possible the persistence of change itself. In other words, it does not take being as its starting point, but process.

This inversion allows us to reread several major figures of the philosophical tradition in a new light.

In Aristotle, being is thought as the passage from potentiality to actuality. Entelechy designates the accomplishment of a form, the realisation of an internal finality. Movement is thus oriented towards a term, a completed form that constitutes its truth. Bonni's Principle does not contradict this dynamic, but shifts its centre of gravity: it is no longer completion that defines existence, but the prolonged maintenance of a state that is never completely finished. Where Aristotle sees in act an accomplishment, the Principle sees an unstable equilibrium, constantly reactualised.

With Spinoza, thought partly leaves the register of finality to introduce an internal dynamic: conatus, that effort by which each thing perseveres in its being. But this effort, although fundamental, remains undetermined as to its structure. It affirms a tendency, without spelling out its conditions of possibility. Bonni's Principle can be understood as an attempt at a minimal formalisation of this type of dynamic: persevering does not simply consist in lasting, but in continually resolving a tension between constraints and dissipation.

Bergson, for his part, radicalises the critique of static conceptions by affirming the primacy of becoming. Duration, élan vital, the continuous flux of consciousness oppose any reduction of existence to fixed states. Yet this thought of flux remains essentially descriptive and intuitive. It shows that existence is movement, but does not specify under what conditions such movement can maintain itself without dissolving. Bonni's Principle stands at this precise point: not to describe becoming, but to state its minimal constraints.

Finally, in Heidegger, the question of being is reformulated starting from human existence itself. Dasein is not a thing, but a being‑in‑project, open to its own possibilities, structured by time and finitude. This approach radically displaces metaphysics towards an analytic of existence. But it leaves in suspense the question of the structural conditions of the real as such. Bonni's Principle does not oppose this perspective; it precedes it. It does not deal with the meaning of existence, but with what makes it possible for there to be something like an existence.

If we turn to Eastern traditions, the contrast with Western metaphysics is less marked. Buddhism, with the doctrine of impermanence (anicca), affirms that all things are in becoming, without stable substance. Likewise, Taoism conceives the real as a spontaneous process, a flux without fixed origin or external finality. These intuitions converge with the idea that existence cannot be reduced to a state.

However, these traditions, despite their depth, do not formulate the structural conditions of this becoming. They give an existential, sometimes practical or spiritual understanding of it, but not a characterisation in terms of minimal constraints. Bonni's Principle can thus be understood as an attempt to reformulate, in a rigorous conceptual language, this intuition of a fundamentally processual real.

This survey reveals a common fault line: either one thinks being as that which maintains itself, at the risk of freezing the real, or one thinks becoming as flux, at the risk of losing all structure. Bonni's Principle proposes a third way: to think existence as a structured process, that is, as a constrained becoming, whose stability rests neither on an immobile substance nor on an indeterminate flux, but on the continuous resolution of an internal tension.

Relevance to scientific theories

The problem of fine‑tuning

Contemporary physics observes that the fundamental constants of the universe (fine‑structure constant, mass ratios, vacuum energy density, etc.) appear to be tuned with remarkable precision to allow the emergence of complex structures. This fine‑tuning has given rise to various interpretations: weak anthropic principle (we can only observe a universe compatible with our existence), strong anthropic principle (the universe must be such as to produce observers), or the multiverse hypothesis (our universe is only one realisation among an infinity of others).

Bonni's Principle offers a distinct perspective. It does not assert that the universe is tuned to produce life or consciousness. It suggests that the observed structures (constants, laws, symmetries) could be the only stable configurations under a minimal set of invariable constraints with dissipation. In other words, what we call fine‑tuning would not be an external adjustment, but the necessary manifestation of a regime of prolonged resolution. The universe is not adjusted for something; it is the form that an existential process subject to minimal conditions inevitably takes.

This approach shifts the question: it is no longer a matter of asking why these values rather than others, but of determining whether another set of values could satisfy the same constraints. If the answer is negative, fine‑tuning loses its contingent character to become a structural property of the regime of existence itself.

The arrow of time

The second law of thermodynamics imposes a direction on macroscopic time: the entropy of an isolated system can only increase. This thermodynamic arrow contrasts with the reversibility of microscopic laws. Bonni's Principle integrates a fundamental irreversibility from the outset via the dissipation mechanism. The part not absorbed by the constraints is continuously dissipated, which implies a global orientation of the process.

In this perspective, the arrow of time is not a contingent emergent property linked to the initial conditions of the universe. It is constitutive of the regime of resolution itself. A process without dissipation would be reversible and could, in principle, return to a previous state. The dissipation required by Bonni's Principle introduces a fundamental asymmetry between before and after. Oriented time thus becomes a necessary condition of existence as a prolonged process.

The emergence of complexity

Physics, chemistry and biology describe a hierarchy of structures of increasing complexity: particles, atoms, molecules, cells, organisms, societies. Bonni's Principle does not claim to explain each level in detail. It suggests, on the other hand, that this hierarchy can be understood as the consequence of a process of prolonged resolution.

A system that maintains a non‑fixed state under invariable constraints and with dissipation necessarily explores the space of compatible configurations. Some of these configurations are more stable than others, not in the sense of a static equilibrium, but in the sense of a greater capacity to maintain the resolution. Complexity would thus emerge as a side effect of this exploration: structures that manage to integrate dissipation more effectively, or to use the dissipated part to fuel their own maintenance, tend to stabilise and become more complex.

This reading requires no finality. It proposes a purely structural selection mechanism, based on compatibility with the minimal constraints and dissipation.

Questions raised by the Principle

Time

If existence is a process of prolonged resolution, time cannot be a pre‑existing dimension in which this process unfolds. Bonni's Principle leads to considering time as a relation of order internal to the process itself. Succession is not an empty framework; it is the expression of the fact that resolution is never complete and that dissipation orients the system irreversibly.

An immediate ontological consequence follows: there is no “before” existence. The simultaneous resolution of the two conditions constitutes existence itself; outside this resolution, there is neither process nor temporality. Time is not a prior container into which existence would come to lodge: it emerges with it, as the internal structure of prolonged resolution.

Symmetrically, there is no programmed end. As long as the two conditions persist — non‑fixed state under invariable constraints and dissipation of the non‑absorbed part — the process maintains itself. No term is inscribed in the set of constraints itself. Existence, in this sense, knows neither absolute beginning nor necessary extinction: it lasts as long as the resolution lasts.

This conception aligns with certain relational approaches to time in physics, but grounds them on a minimal ontological requirement rather than on a postulated geometric structure.

Chance

Bonni's Principle does not explicitly mention chance. It evokes a minimal and invariable set of constraints, which might suggest strict determinism. However, the existence of a non‑absorbed part and a dissipation mechanism introduces a form of functional indeterminacy. The system cannot be entirely predictable, because dissipation is by nature a process that escapes complete determination by the constraints.

This indeterminacy is not chance in the sense of an absence of cause, but an irreducible openness in the determination of the system. It could provide a framework for thinking the articulation between deterministic laws and quantum fluctuations, without postulating two distinct ontological regimes.

Evolution

Theories of biological evolution describe a mechanism of variation, heredity and natural selection. Bonni's Principle does not substitute for these mechanisms, but it can shed light on their condition of possibility. For evolution to operate, a substrate is needed that is capable of maintaining forms while allowing their variation, and capable of integrating a dissipation (mortality, predation, competition). Bonni's Principle provides the minimal ontological framework for such a process to be possible: a non‑fixed state under invariable constraints, with dissipation.

Darwinian evolution then appears as a particular realisation, in the biological domain, of the general regime of resolution described by the Principle. It is not a logical deduction, but a structural compatibility.

God and finality

Bonni's Principle contains no reference to a transcendent cause. It describes a regime of resolution entirely defined by a minimal and invariable set of constraints. This set being invariable, the process is fully determined at its fundamental level: no external intervention is required to ensure its course, nor even conceivable without altering the constraints themselves, which would amount to changing the nature of the process.

Moreover, the assertion that “there is then a confusion of physical reality with its mathematical description” carries a decisive consequence. If the formal structure of the process coincides with the reality of the process itself, then the rules are not imposed from outside. They do not pre‑exist existence as a plan separate from its execution. They are the process as it unfolds. There is no external legislator, because there is no exteriority of formalism in relation to what it formalises.

This does not strictly exclude the hypothesis of a transcendent principle that would be the ultimate reason for the very existence of the set of constraints. But it excludes any divine intervention in the course of the process, as well as any external finality. If there is finality, it can only be immanent: the perpetuation of the process is its own end. Bonni's Principle is therefore compatible with a form of abstract deism (a principle that accounts for the existence of the set of constraints), but incompatible with an interventionist theism or with a superimposed teleology.

If the idea of God cannot be maintained as a principle external to the real without contradicting the framework of Bonni's Principle, it can on the other hand be understood as an emergence proper to conscious systems, producing representations of finality or origin. The idea of God thus appears as a construction internal to the real which, while not constituting its foundation, cannot be rigorously excluded. This undecidability makes it both its strength and its paradox: born of the process, it remains, for the consciousness that produces it, irreducibly open as to its scope.

Man

Integrating the human being into the framework of Bonni's Principle requires renouncing any form of ontological exceptionalism. If existence is rigorously defined as a process of prolonged resolution, man cannot be its prime mover or its architect. [cite_start]He appears, on the contrary, as a late and sophisticated product of this regime of coherence.

Human action under the rule of laws

[cite_start]Man is not existence itself; he is a particular manifestation of the universe, itself maintained by the minimal and invariable set of constraints that defines its process. In this metaphysical perspective, human action is not a subtraction from fundamental laws, but an expression of their persistence. We are moved and maintained by these rules included in the process of resolution. Consequently, the individual can never extract himself from the framework that ensures his own stability. His action, however free it may be in its phenomenological expression, remains an internal modality of the global resolution, a way for the system to continue to “be” by tirelessly processing its share of dissipation.

Consciousness

Consciousness, far from being an immaterial addition or an irreducible mystery, is interpreted here as a crucial evolutionary gain of function. It constitutes a structural response to an environment which, by its thermodynamic and dispersive nature, continually opposes the persistence of the entity. Faced with the assaults of radiation, degradation by heat or the onslaught of disease, consciousness acts as an operator of increased adaptability.

It is the instrument by which the living no longer merely undergoes dissipation, but anticipates and rebalances its non‑fixed state with superior precision. Through reasoning and reflective consciousness, the process of resolution attains a form of dynamic homeostasis capable of handling problems of increasing complexity, thus guaranteeing the persistence of the organic structure over time through reproduction and the management of contingency.

The future

Human evolution can thus be considered as the culmination of organic biological evolution. It represents an optimal solution, and perhaps one that is difficult to surpass in the carbon realm, for satisfying the requirements of Bonni's Principle: maintaining a prolonged equilibrium under constraints while effectively managing a complex dissipation.

However, this summit is not a term. If man is the product of existence, he is also the vector by which this existence explores new configurations. As a being of reason, he could be the one who engenders new forms of complexity, perhaps synthetic or informational, destined to surpass him in the domains of logical resolution and structural persistence. Humanity would then be only a stage in a process of resolution which, faithful to its non‑fixed nature, continues to produce solutions that are increasingly integrated into the minimal set of its original rules.

Bonni's Principle and science

Bonni's Principle, as a philosophical statement, contains in itself no mathematical content. It merely stipulates the abstract conditions that a process must satisfy in order to be qualified as prolonged existence. However, unlike many other metaphysical principles, it offers points of anchorage for science that many philosophies of existence lack. It is not reduced to contemplative thought: it can be employed within a framework of rigorous scientific study.

This is precisely the case with the Theory of Causal Auto‑Coherence (ACC for Auto‑Cohérence Causale in french). ACC is a study that aims to measure the extent to which our universe would be the result of a process guided by Bonni's Principle. It translates the conditions of the Principle into a mathematical formalism and examines whether the coherence constraints it imposes can suffice to engender the observed structures.

The presentation of the results of this study lies outside the scope of this article, which is devoted to the philosophical dimension of the Principle. It remains that certain specific points of physics can be understood as emanating from the Principle, in its own logic.

Quantum mechanics

Quantum mechanics is characterised by several features that resonate with the implications of Bonni's Principle.

Indeterminacy. Heisenberg’s uncertainty relations impose a limit on the joint determination of conjugate quantities. Bonni's Principle, via the part not absorbed by the constraints and its dissipation, introduces a form of incompleteness of determination. Dissipation is by nature a process that escapes complete resolution by the invariable constraints. There is a structural analogy here, without the Principle itself postulating a fundamental constant.

Non‑separability. Quantum correlations violate Bell’s inequalities and manifest a form of holism. Bonni's Principle, by defining existence as a relational process subject to global coherence constraints, provides a framework in which non‑separability is natural: coherence is defined on relations and not on isolated elements.

The measurement problem. Standard quantum theory separates system and observer. Bonni's Principle, by the affirmed identity between physical reality and mathematical description, excludes such an ontological split. All that exists is the process itself, without exteriority. ACC implements this unity by treating measurement as a dissipative interaction internal to the system.

General relativity

Relational space‑time. General relativity has eliminated absolute space and time in favour of a dynamic geometry. Bonni's Principle radicalises this perspective: it does not even postulate space‑time as a primary given. Within the framework of ACC, the spatio‑temporal structure emerges as the continuous limit of a discrete relational substrate.

Initial singularity. Einstein’s equations suggest a temporal beginning in the form of a singularity. Bonni's Principle affirms that there is no “before” existence, which converges with the idea of a joint emergence of time and process. It does not, however, require a singularity: a permanent regime without a temporal edge is equally conceivable.

Quantum gravity and unification theories

Fundamental discreteness. Several approaches to quantum gravity postulate a discrete structure of space‑time at the Planck scale. Bonni's Principle, in its dynamic of resolution under constraints, suggests that a discrete substrate could emerge naturally from the coherence conditions, without it being necessary to postulate it ad hoc.

The problem of time. In canonical quantum gravity, time seems to disappear from the Wheeler‑DeWitt equation. Bonni's Principle, by making dissipation an essential mechanism, reintroduces a temporal arrow at the fundamental level. Time there is the expression of the irreversibility of dissipation, and not an external variable.

The landscape of solutions. Unification theories often predict a vast set of possible solutions, raising the question of the selection of our universe. Bonni's Principle, if the uniqueness of the minimal set of constraints is established, would drastically reduce this space. ACC explores the possibility that the coherence constraints leave only a single class of structural equivalence.

Thermodynamics and irreversibility

Fundamental dissipation. In standard physics, dissipation is an emergent phenomenon linked to the large number of degrees of freedom and loss of information. If the Principle elevates dissipation to the rank of a necessary condition at the most fundamental level, it is nevertheless in its macroscopic manifestations that it is observed and measured.

Intrinsic irreversibility. Bonni's Principle is incompatible with a vision in which microscopic laws would be strictly reversible. It joins approaches that postulate a primitive irreversibility, such as quantum mechanics with wave‑function collapse or certain stochastic extensions.

Critical equilibrium. The regime of constant rebalancing between structuration and dissipation evokes the stationary non‑equilibrium states studied by the thermodynamics of irreversible processes. The Principle could find natural extensions in these formalisms.

Bonni's Principle does not substitute for any existing physical theory. It offers a conceptual framework for questioning their articulation and their foundation. The convergences observed with quantum mechanics, general relativity and approaches to quantum gravity indicate a structural compatibility. ACC, as a formal development of the Principle, constitutes the attempt to give this framework a precise mathematical expression. This attempt demonstrates that Bonni's Principle possesses a rare heuristic virtue: it opens up a space of research where the philosophy of existence and fundamental physics can enter into dialogue.

Conclusion

Bonni's Principle, as set out, presents itself as a minimal philosophical proposition on the conditions of an existence understood as a process. It does not claim to substitute for the natural sciences or for constituted ontologies, but offers a conceptual framework for questioning their articulation.

Its possible fruitfulness lies in its capacity to provide a common scheme for fields as diverse as cosmology, thermodynamics, quantum theory or evolutionary biology, without surreptitiously importing heavy metaphysical presuppositions. In this, it could contribute to a renewal of the dialogue between the philosophy of existence and the natural sciences.

The systematic exploration of this fruitfulness remains to be carried out. It constitutes the horizon of research opened by the statement of the Principle.

Bonni's Principle, in itself, states no restriction as to the number of entities satisfying its conditions. It therefore in no way forbids the coexistence of a plurality of existences, which one could call multiple universes. Nothing excludes that other universes exist with the same minimal set of invariable constraints as our own. If that were the case, these universes would be structurally indistinguishable from ours as regards their fundamental laws. On the other hand, if a universe were possible with a different set of rules, it would be governed by fundamental relations other than those that define our own structure — like a space where the ratio of circumference to diameter differed from π, or were not even constant. Such a universe would not be incoherent in itself, but it would in principle escape our intelligence, the latter itself being founded on the constraints that govern our universe. Our mathematical categories, forged in and by this set of rules, could not grasp it. The uniqueness of the set of constraints for any intelligible universe, if established, therefore does not demonstrate the uniqueness of existence, but it circumscribes the domain of what can be understood to that which shares our own formal conditions.