public final ANTLRv3TreeFilter.rewrite_tree_block_return rewrite_tree_block() throws RecognitionException {
        ANTLRv3TreeFilter.rewrite_tree_block_return retval = new ANTLRv3TreeFilter.rewrite_tree_block_return();
        retval.start = input.LT(1);

        try {
            // back-end/koopa/trees/antlr/filter/generator/ANTLRv3TreeFilter.g:429:5: ( ^( BLOCK rewrite_tree_alternative EOB ) )
            // back-end/koopa/trees/antlr/filter/generator/ANTLRv3TreeFilter.g:429:9: ^( BLOCK rewrite_tree_alternative EOB )
            {
            match(input,BLOCK,FOLLOW_BLOCK_in_rewrite_tree_block2177); 

            match(input, Token.DOWN, null); 
            pushFollow(FOLLOW_rewrite_tree_alternative_in_rewrite_tree_block2179);
            rewrite_tree_alternative();

            state._fsp--;

            match(input,EOB,FOLLOW_EOB_in_rewrite_tree_block2181); 

            match(input, Token.UP, null); 

            }

        }
        catch (RecognitionException re) {
            reportError(re);
            recover(input,re);
        }
        finally {
        }
        return retval;
    }