why G = abs(A[L, K]); give me error ?

Please I need to ABS a number of Matrix with two dimension where is I mistache ?
G = abs(A [L,K]) ; A[L,K] is only a number with two dimension thank you

exit status 1
macro "abs" passed 2 arguments, but takes just 1

G = abs(A [L,K]) ;
Maybe remove the space between A and [ ?

Did you mean [L][K] ?