query: Kripke models - prove that formula is not tautology in intuitionistical logic
positive_passages.docid: 143999
positive_passages.text: Prove that formula is not tautology.
negative_passages.docid: 45481
negative_passages.text: Prove or disprove validity: $(\forall x \exists y (P(x) \supset Q(y))) \supset(\exists y \forall x (P (x) \supset Q(y)))$
negative_passages.docid: 101163
negative_passages.text: Does there exist a universal formula of first-order logic that is satisfiable only by structures with infinite domains?
negative_passages.docid: 140194
negative_passages.text: Using natural deduction to prove that $p \implies q \vdash \lnot p \lor q$
negative_passages.docid: 87928
negative_passages.text: Proof of logical equivalence of biconditional and other proposition
negative_passages.docid: 103653
negative_passages.text: Interpretations and models in propositional logic
negative_passages.docid: 91861
negative_passages.text: Propositional Logic: p → q, ¬p → r, ¬q → ¬r ⊢ q
negative_passages.docid: 86248
negative_passages.text: Is $\exists x(x=a)$ a valid formula in first order logic with equality?
negative_passages.docid: 125950
negative_passages.text: Proof strategy involving first order logic for existential quantification at very beginning
negative_passages.docid: 109159
negative_passages.text: What's the intuition behind $(\exists y)(\mathscr{C}(y)\supset\mathscr{D})\supset((\forall x)\mathscr{C}(x)\supset\mathscr{D})$
negative_passages.docid: 65895
negative_passages.text: Irrationality proofs not by contradiction
negative_passages.docid: 120065
negative_passages.text: Niven’s theorem proof.
negative_passages.docid: 72034
negative_passages.text: Truth table and the meaning of $\oplus$ in propositional logic
negative_passages.docid: 70117
negative_passages.text: Show that $(p \to q) \lor (q \to p)$ is a tautology
negative_passages.docid: 31212
negative_passages.text: The existence of the empty set is an axiom of ZFC or not?
negative_passages.docid: 138897
negative_passages.text: help with some Hilbert style proofs in a propositional logic axiom system.
negative_passages.docid: 122684
negative_passages.text: How do you prove Well-Ordering without Mathematical Induction? (and vice-versa)