class
Cslib.Logic.LogicalEquivalence
(Proposition : Type u)
[HasContext Proposition]
(Judgement : Type v)
[HasHContext Judgement Proposition]
(Valid : Judgement → Sort w)
:
Sort (max (max (u + 1) (u_2 + 1)) w)
A logical equivalence for a given type of Judgements is a congruence on propositions that
preserves validity of judgements under any judgemental context.
- eqv (a b : Proposition) : Prop
The logical equivalence relation.
- congruence : Congruence Proposition (eqv Valid)
Proof that
eqvis a congruence. - eqv_fill_valid {a b : Proposition} (heqv : eqv Valid a b) (c : HasHContext.Context Judgement Proposition) (h : Valid c<[a]) : Valid c<[b]
Validity is preserved for any judgemental context.
Instances
The logical equivalence relation.
Equations
- Cslib.Logic.«term_≡_» = Lean.ParserDescr.trailingNode `Cslib.Logic.«term_≡_» 29 30 (Lean.ParserDescr.binary `andthen (Lean.ParserDescr.symbol " ≡ ") (Lean.ParserDescr.cat `term 30))