Used as a Function
Monadic Back Slash is not defined
Dyadic Back Slash means
3 ¯2 4 \ 7 8
7 7 7 0 0 8 8 8 8
1 0 1 0 1 \ 'Hat'
H a t
Used as an Operator
Back Slash is a Monadic operator with a Dyadic operand
Operator Back Slash means
+\ 1 2 3 4 5
1 3 6 10 15
mat
1 2 3 4
5 6 7 8
9 10 11 12
+\ mat
1 3 6 10
5 11 18 26
9 19 30 42
+\[1] mat
1 2 3 4
6 8 10 12
15 18 21 24