$\snippet{name: op_column, sign: '+', x: '36', y: '27', z: ''}$;
$\snippet{name: op_column, sign: '-', x: '70', y: '53', z: ''}$;
$\snippet{name: op_column, sign: '+', x: '45', y: '18', z: ''}$;
$\snippet{name: op_column, sign: '-', x: '92', y: '65', z: ''}$.

$\snippet{name: op_column, sign: '+', x: '36', y: '27', z: '63'}$
$\snippet{name: op_column, sign: '-', x: '70', y: '53', z: '17'}$
$\snippet{name: op_column, sign: '+', x: '45', y: '18', z: '63'}$
$\snippet{name: op_column, sign: '-', x: '92', y: '65', z: '27'}$