internal override int VisitFalse(FalseExpr <T_Identifier> expression) { return(0); }
internal override BoolExpr <T_Identifier> VisitFalse(FalseExpr <T_Identifier> expression) { return(expression); }
internal abstract T_Return VisitFalse(FalseExpr <T_Identifier> expression);
internal override Vertex VisitFalse(FalseExpr <T_Identifier> expression) { return(Vertex.Zero); }
internal override BoolExpr <T_To> VisitFalse(FalseExpr <T_From> expression) { return(FalseExpr <T_To> .Value); }
internal override bool VisitFalse(FalseExpr <T_Identifier> expression) { return(true); }