mettalog doesnt evaluate with nested match

[drspro]

; probably collapse add
; (sudoku_board 9 7 9 7 )
; (sudoku_puzzle_state 1 1 5 )

(= (sudoku_quad_num $rowx $colx)
(match &self ( sudoku_board $rowx $colx $quadn $nothing )
$quadn ) )

(= (get_quad_stateyz $quadn)
(match &self ( sudoku_puzzle_state $row $colx $state ) (
(if (and (> $state 0) (== (sudoku_quad_num $row $colx) $quadn ) )
(cell_xstate $row $colx $state)
(empty)
) ) )
)