def del_expr(self, ctx):
        """
        Returns the MUF needed to delete a given lvalue. (ie: array item)
        Returned MUF will set a bare variable to 0, and will remove the
        given indexed item for an indexed array or dictionary.
        """
        if self.readonly:
            raise MuvError(
                "Cannot assign value to constant '%s'." % self.varname,
                position=self.position
            )
        varname = ctx.lookup_variable(self.varname)
        if varname is None:
            raise MuvError(
                "Undeclared identifier '%s'." % self.varname,
                position=self.position
            )
        if len(self.indexing) == 0:
            return "0 {var} !".format(var=varname)
        if len(self.indexing) == 1:
            if ctx.target in ['fb7']:
                return "{var} @ {idx} array_delitem".format(
                    var=varname,
                    idx=self.indexing[0].generate_code(ctx),
                )
            else:
                return "{var} @ {idx} array_delitem dup {var} !".format(
                    var=varname,
                    idx=self.indexing[0].generate_code(ctx),
                )
        if ctx.target in ['fb7']:
            return "{var} @ {{ {idx} }}list array_nested_del".format(
                var=varname,
                idx=" ".join(x.generate_code(ctx) for x in self.indexing),
            )
        else:
            return "{var} @ {{ {idx} }}list array_nested_del dup {var} !".format(
                var=varname,
                idx=" ".join(x.generate_code(ctx) for x in self.indexing),
            )