fact: Definition IS_FROM_TYPE := ProdType (ProdType (ProdType (ProdType (ConstType share) (ConstType val)) (ConstType Z)) (ConstType val)) Mpred.
imports: VST.veric.rmaps CertiGraph.lib.List_ext CertiGraph.graph.graph_model CertiGraph.CertiGC.GCGraph CertiGraph.CertiGC.spatial_gcgraph CertiGraph.CertiGC.env_graph_gc CertiGraph.msl_ext.iter_sepcon