Predicate Logic Equivalences
108837
How to show that $\vdash (\forall x \beta \to \alpha) \leftrightarrow \exists x (\beta \to \alpha)$?
42590
Understanding implication in logic truth tables (excerpt from textbook)
51369
Natural deduction proof of $p \lor (p\implies q)$ with propositional calculus
158016
Help understanding predicate logic question/proof
89506
Union of disjoint sets : Equivalence relations
62936
Proving equivalencies of two versions of the Axiom of Choice
20030
Is an equivalence an adjunction?
89167
Cardinality of equivalence relations in $\mathbb{N}$
36566
Equivalence classes and metric spaces
46423
Distributivity of quantifiers over logical connectives
87928
Proof of logical equivalence of biconditional and other proposition
53199
First-Order Logic: Formalisation of the phrase "Not all that glitters is gold"
85507
Equivalence Relation problem
43655
Verify is tautology by using logical equivalence
48368
Prove using Natural Deduction in predicate logic $(\forall x\ P(x))\to Q ⊢ \exists x (P(x)\to Q)$
96504
First-Order Logic vs. Second-Order Logic
142840
Open axioms of equality