Implication as defined in mathematical logic
52322
Implication in mathematics - How can A imply B when A is False?
158016
Help understanding predicate logic question/proof
45481
Prove or disprove validity: $(\forall x \exists y (P(x) \supset Q(y))) \supset(\exists y \forall x (P (x) \supset Q(y)))$
129652
Meaning of "strong" and "weak" (formulas?) in propositional logic
50733
Help to understand material implication
65379
Deriving $\neg R$ from $\{R↔(R∨(P∧¬P)), R↔¬P, ¬P→(P↔(Q→Q)), P→Q\}$
86248
Is $\exists x(x=a)$ a valid formula in first order logic with equality?
61303
"Infer" vs. "imply" — can "infer" imply "imply"?
62358
Implications and Ordinary language
46160
What is the difference between implication symbols: $\rightarrow$ and $\Rightarrow$?
140682
Proving a property of a Logic Formal Language
122184
De Morgan's laws in logic and set theory
49994
Deduction of $\forall y \exists x (x=y)$
56351
Prove that these statements $(A \lor \neg B)$ and $\neg A \to \neg B$ are logically equivalent
32244
Propositional Logic - Deduction
125950
Proof strategy involving first order logic for existential quantification at very beginning
126870
Show that axiom of replacement implies from the Axiom of Specification [Proof Verification]