feat(library/init/sigma_lex): add lex_ndep for sigma types
feat(library/init/sigma_lex): add lex_ndep for sigma types

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