- singletonSubst checks whether the variable is mapped to itself (and if so, it returns the empty substitution) - When instantiating, we build a substitution without the "listToSubst" constructor, since we might violate the idempotency property that is checked for.
- singletonSubst checks whether the variable is mapped to itself (and if so, it returns the empty substitution)
- When instantiating, we build a substitution without the "listToSubst" constructor, since we might violate the idempotency property that is checked for.

git-svn-id: bcf1007ea3ea39647a31cb6b6eab17d5210c51ee@1123 d9a34ac6-6904-0410-8848-93d71bbb9804

ideas-edu/ideas