.replaceAll("@x", "x").replaceAll("@PUNx", ""));
renameArg(gem, 0, "x", "y");
renameArg(gem, 1, "z", "x");
SourceElement element = createFunctionDefn("y x", code
.replaceAll("%x", "y").replaceAll("%z", "x")
.replaceAll("@x", "x_1").replaceAll("@PUNx", "=x_1"));
assertFunctionTextEquals(gem, element);
}