$\snippet{name: op_column, sign: '+', x: '75', y: '25', z: '100'}$
 
$\snippet{name: op_column, sign: '-', x: '64', y: '28', z: '36'}$
 
$\snippet{name: op_column, sign: '+', x: '37', y: '49', z: '86'}$
 
$\snippet{name: op_column, sign: '-', x: '96', y: '27', z: '69'}$