initial check for unknown words in parsing

examples/regulus/toy0/Toy0Fre.gf

@@ -0,0 +1,30 @@
+concrete Toy0Fre of Toy0 = {
+
+param
+  Number = Sg | Pl ;
+  Gender = Masc | Fem ;
+
+lincat
+  Spec = {s : Gender => Str ; n : Number} ;
+  Noun = {s : Number => Str ; g : Gender} ;
+  MAIN,NP = {s : Str} ;
+
+lin
+  Main np = np ;
+  SpecNoun spec noun = {s = spec.s ! noun.g ++ noun.s ! spec.n} ;
+
+  One = {s = table {Fem => "une" ; _ => "un"} ; n = Sg} ;
+  Two = {s = \\_ => "deux" ; n = Pl} ;
+
+  Felis = mkNoun "chat" Masc ;
+  Canis = mkNoun "chien" Masc ;
+
+oper
+  mkNoun : Str -> Gender -> {s : Number => Str ; g : Gender} = \s,g -> {
+    s = table {
+      Sg => s ;
+      Pl => s + "s"
+      } ;
+    g = g
+    } ;
+}