[TC] put cnonical projection in tc namespace

Author: FissoreD

apps/tc/elpi/tc_aux.elpi

@@ -212,10 +212,10 @@ namespace tc {
     term ->          % The current precompiled subterm: shape is app[app[X,PF],NPF]
     list term ->     % The eta-expanded version of X, from X^{len(PF)} to X^{len(PF)+len(NPF)}
     term.
-}
 
-type tc.canonical-projection
-  term ->       % The current precompiled subterm
-  list term ->  % The list of FV in the precomp subterm
-  int ->
-  term.
+  type canonical-projection
+    term ->       % The current precompiled subterm
+    list term ->  % The list of FV in the precomp subterm
+    int ->
+    term.
+}