simplify mkSkolem naming system: don't use $$

Short summary: By default NODEID is appeneded, just continue doing what you
were, just don't add the _$$ at the end.

Long summary:

Before this commit there were four (yes!) ways to specify the names for new
skolems, which result in names as given below

1) mkSkolem("name", ..., SKOLEM_FLAG_DEFAULT)  -> "name_NODEID"
2) mkSkolem("name", ..., SKOLEM_EXACT_NAME)  -> "name"
3) mkSkolem("name_$$", ..., SKOLEM_FLAG_DEFAULT) -> "name_NODEID"
4) mkSkolem("na_$$_me", ..., SKOLEM_FLAG_DEFAULT) -> "na_NODEID_me"

After this commit, only 1) and 2) stay.

90% usage is of 1) or 3), which results in exact same behavior (and
looking at the source code it doesn't look like everyone realized that
the _$$ is just redundant).

Almost no one used 4), which is the only reason to even have $$. Post this
commit if you really want a number in the middle, manually construct the
name and use the SKOLEM_EXACT_NAME flag.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/theory/builtin/theory_builtin_type_rules.h b/src/theory/builtin/theory_builtin_type_rules.h
index c7143bdeb..0ebcb31e8 100644
--- a/src/theory/builtin/theory_builtin_type_rules.h
+++ b/src/theory/builtin/theory_builtin_type_rules.h
@@ -227,7 +227,7 @@ public:
   }
   inline static Node mkGroundTerm(TypeNode type) {
     Assert(type.getKind() == kind::SORT_TYPE);
-    return NodeManager::currentNM()->mkSkolem("groundTerm_$$", type, "a ground term created for type " + type.toString());
+    return NodeManager::currentNM()->mkSkolem("groundTerm", type, "a ground term created for type " + type.toString());
   }
 };/* class SortProperties */