fix(library/init/sigma): make sure file compiles even when '--to_axiom' is used
fix(library/init/sigma): make sure file compiles even when '--to_axiom' is used

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