how to find the first element for each row which satisfy the condition
suppose i have a table t: ([]isMatched: (1b,1b,0b,0b;1b,1b,0b,0b;0b,0b,1b,1b); index:((0,1,2,3);(0,1,2,3);(0,1,2,3));id: ((`a,`b,`c,`d);(`a,`b,`c,`d);(`a,`b,`c,`d))) so each row will find use the first element in idx which the corresponding element i...