feat(library/algebra/binary): add auxiliary theorems
feat(library/algebra/binary): add auxiliary theorems

soonhokong/lean,UlrikBuchholtz/lean,digama0/lean,soonhokong/lean-osx,johoelzl/lean,leanprover-community/lean,avigad/lean,leanprover-community/lean,htzh/lean,soonhokong/lean-osx,htzh/lean,Kha/lean,UlrikBuchholtz/lean,leanprover/lean,levnach/lean,soonhokong/lean-osx,Kha/lean,rlewis1988/lean,dselsam/lean,soonhokong/lean-osx,leanprover-community/lean,leodemoura/lean,javra/lean,javra/lean,soonhokong/lean,eigengrau/lean,rlewis1988/lean,digama0/lean,fpvandoorn/lean,avigad/lean,fpvandoorn/lean2,fpvandoorn/lean,Kha/lean,leanprover/lean,soonhokong/lean-windows,soonhokong/lean-windows,Kha/lean,avigad/lean,sp3ctum/lean,levnach/lean,Kha/lean,leodemoura/lean,leanprover-community/lean,fpvandoorn/lean2,leodemoura/lean,digama0/lean,leanprover/lean,rlewis1988/lean,johoelzl/lean,leanprover/lean,fpvandoorn/lean,sp3ctum/lean,levnach/lean,avigad/lean,sp3ctum/lean,leanprover-community/lean,leanprover/lean,eigengrau/lean,levnach/lean,UlrikBuchholtz/lean,digama0/lean,fpvandoorn/lean,fpvandoorn/lean2,rlewis1988/lean,fgdorais/lean,digama0/lean,soonhokong/lean,leanprover-community/lean,fpvandoorn/lean2,johoelzl/lean,UlrikBuchholtz/lean,johoelzl/lean,leodemoura/lean,soonhokong/lean,c-cube/lean,htzh/lean,johoelzl/lean,rlewis1988/lean,avigad/lean,fgdorais/lean,fgdorais/lean,UlrikBuchholtz/lean,johoelzl/lean,eigengrau/lean,htzh/lean,fpvandoorn/lean,rlewis1988/lean,c-cube/lean,c-cube/lean,soonhokong/lean-windows,dselsam/lean,javra/lean,avigad/lean,soonhokong/lean-windows,c-cube/lean,soonhokong/lean,sp3ctum/lean,leodemoura/lean,javra/lean,dselsam/lean,leanprover/lean,soonhokong/lean-osx,Kha/lean,fpvandoorn/lean2,levnach/lean,leodemoura/lean,fgdorais/lean,fgdorais/lean,eigengrau/lean,javra/lean,dselsam/lean,digama0/lean,soonhokong/lean-windows,sp3ctum/lean,dselsam/lean,fpvandoorn/lean,fgdorais/lean,c-cube/lean,htzh/lean,eigengrau/lean,dselsam/lean