fix(library/type_context): make sure all assigned metavariables are substituted
fix(library/type_context): make sure all assigned metavariables are substituted

fpvandoorn/lean,dselsam/lean,Kha/lean,leanprover/lean,fpvandoorn/lean,fpvandoorn/lean,leodemoura/lean,dselsam/lean,fpvandoorn/lean,leanprover-community/lean,leanprover/lean,leodemoura/lean,leanprover/lean,leanprover-community/lean,leanprover-community/lean,Kha/lean,dselsam/lean,dselsam/lean,leanprover-community/lean,dselsam/lean,leanprover/lean,digama0/lean,leanprover-community/lean,digama0/lean,leanprover-community/lean,dselsam/lean,Kha/lean,leodemoura/lean,leanprover/lean,Kha/lean,digama0/lean,fpvandoorn/lean,leodemoura/lean,Kha/lean,Kha/lean,leodemoura/lean,digama0/lean,digama0/lean,leanprover/lean,fpvandoorn/lean,leodemoura/lean,digama0/lean