Commit 2024-07-23 12:07 3cd501d4
View on Github →refactor: Make Frame
extend HeytingAlgebra
(#10560)
It is mathematically true that a frame is a Heyting algebra. However we want nice defeqs, so we can't just provide an instance defining himp
as some supremum. Instead, we need Frame
to directly extend HeytingAlgebra
.