+class EncodingGraph;
+class EncodingNode;
+class EncodingEdge;
+class EncodingSubGraph;
+class SignatureEnc;
+class Signature;
+class ValuedSignature;
+class AlloyElementSig;
+class AlloySetSig;
+class AlloyBoolSig;
+struct IncrementalSolver;
+typedef struct IncrementalSolver IncrementalSolver;
+struct TableEntry;
+typedef struct TableEntry TableEntry;