Group is

        ../../ast/sources.cm

	../copy/copy-ast-sig.sml
	../copy/copy-ast.sml

	simplify-ast-sig.sml
	simplify-ast.sml

#if (defined(d))
        extensions/d/eq-ast-ext.sml
#else
        extensions/c/copy-ast-ext.sml
        extensions/c/simplify-ast-ext.sml

#endif
