feat(library/blast/congruence_closure): add is_eqv
feat(library/blast/congruence_closure): add is_eqv

soonhokong/lean,fpvandoorn/lean,Kha/lean,fgdorais/lean,avigad/lean,soonhokong/lean-windows,dselsam/lean,rlewis1988/lean,fpvandoorn/lean2,soonhokong/lean-osx,leanprover-community/lean,leanprover/lean,leodemoura/lean,soonhokong/lean,soonhokong/lean-windows,leanprover/lean,dselsam/lean,digama0/lean,leanprover/lean,levnach/lean,leanprover-community/lean,UlrikBuchholtz/lean,fgdorais/lean,dselsam/lean,avigad/lean,javra/lean,johoelzl/lean,Kha/lean,leanprover-community/lean,rlewis1988/lean,javra/lean,rlewis1988/lean,digama0/lean,UlrikBuchholtz/lean,fpvandoorn/lean,leanprover-community/lean,soonhokong/lean-windows,rlewis1988/lean,soonhokong/lean-osx,fpvandoorn/lean,dselsam/lean,digama0/lean,johoelzl/lean,leanprover-community/lean,leanprover/lean,levnach/lean,javra/lean,leodemoura/lean,soonhokong/lean-windows,fpvandoorn/lean2,johoelzl/lean,Kha/lean,fpvandoorn/lean2,avigad/lean,leodemoura/lean,johoelzl/lean,UlrikBuchholtz/lean,leodemoura/lean,leanprover/lean,avigad/lean,leodemoura/lean,Kha/lean,rlewis1988/lean,levnach/lean,leanprover/lean,avigad/lean,javra/lean,digama0/lean,leanprover-community/lean,javra/lean,johoelzl/lean,soonhokong/lean-osx,UlrikBuchholtz/lean,rlewis1988/lean,digama0/lean,soonhokong/lean-osx,soonhokong/lean,soonhokong/lean,Kha/lean,digama0/lean,fpvandoorn/lean2,johoelzl/lean,dselsam/lean,dselsam/lean,soonhokong/lean-windows,levnach/lean,fgdorais/lean,fgdorais/lean,fpvandoorn/lean,fpvandoorn/lean2,Kha/lean,UlrikBuchholtz/lean,levnach/lean,fgdorais/lean,avigad/lean,fpvandoorn/lean,fpvandoorn/lean,soonhokong/lean,fgdorais/lean,leodemoura/lean,soonhokong/lean-osx