Questions tagged [modal-logic]
a type of formal logic primarily developed in the 1960s that extends classical propositional and predicate logic to include operators expressing modality
37 questions from the last 365 days
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Nothing is impossible [closed]
While contemplating what must be necessary metaphysically, one ought to come to the sentence:"Nothing is impossible".
As one argues the triviality: L=~~M, where I use L- for necessary and M- ...
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What enforces the laws of physics? [closed]
Constructor theory reframes physics in terms of which tasks are possible or impossible; expressed via counterfactual constraints rather than dynamical laws.
If such constraints are taken to be ...
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Modal pluralism and divine attributes - appropriate logics [closed]
I'm exploring an idea, the basic concept is that its better to treat Divine Attributes as modal profiles in their own modal space then using grounding theory to analyse the attributes and then map ...
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Metaphysical grounding: Why is “necessarily, if pious then 2+3=5” relevant in the grounding vs. modality debate?
In the SEP entry on Metaphysical Grounding, Lowe argues that grounding cannot be reduced to purely modal notions, since modality is “too coarse-grained.” He illustrates this with the following claim:
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Can Buridan’s formula be rewritten to the following using the standard translation of modal logic?
Can Buridan’s formula be rewritten to the following using the standard translation of modal logic?
There exists a world where for all X, X is an element of this world if and only if X is God. ...
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Can modal logic statements be translated into FOL statements?
Can modal logic statements be translated into FOL statements? I ask because of the following statement: There exist X such that X is necessarily a man. Let W be the world variable. Then the statement ...
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the Distinctions Between Biconditional entailment, Conceptual, and Metaphysical Necessity in Kramer’s Analysis of Hohfeldian Entitlements
Could you help me resolve a difficulty I’m having in Kramer’s discussion of Hohfeld? Kramer emphasizes that there is no biconditional entailment between horizontal entitlements such as liberties and ...
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Why are modal constraints valid/invalid and not true/false?
I'm reading "Separating Rules from Normativity" by Jaap Hage which is about the philosophy of rules and in it he states that the "soft" modal constraints we put on possible worlds ...
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Do Numbers Necessarily Exist? [closed]
Something necessarily exists if it exists in all possible worlds.
With this being said, do numbers necessarily exist?
I ask because of the following: Consider the number 1. If we hold that the number ...
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Is the following valid in modal logic [duplicate]
Is the following valid in modal logic: ∃X(□AX)→□∃X(AX)? I ask because I keep getting different answers from different websites. According to the tree proof generator it is valid:https://www.umsu.de/...
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Extending inference rules for normal modal logic
I know that we can use BAOs or general frames as complete semantics for normal modal logic, but is there any way to extend the inference rules of normal modal logics/extend normal modal logics in a ...
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Is it inconsistent to lack belief in proposition A and lack belief in its negation?
Is there some axiom or theorem that 'prohibits' believing neither in proposition A nor in its negation simultaneously?
To clarify: clearly there's no contradiction in believing A and lacking belief in ...
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Understanding Contingency: interactions of Distribution Axiom and Argument from Contingency and Principle of Sufficient Reason
I have a strong suspicion that I have some sort of fundamental misunderstanding of contingency, and this misunderstanding is causing me to have trouble understanding the interaction between three '...
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The rule of necessitation seems utterly unreasonable
The rule of necessitation as usually stated ("if p can be deduced without assumptions, then p is necessarily true") seems all in all reasonable. What seems unreasonable is an equivalent ...
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How can we understand Chihara’s constructibility theory?
I am currently reading Chihara’s 1990 book Constructibility and Mathematical Existence.
In order to explain what it means for a sentence with the constructibility quantifier to be true, Chihara begins ...
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