fix(library/init/nat): missing annotations
fix(library/init/nat): missing annotations

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