NB: More recent documentation for Dyalog APL is available at https://docs.dyalog.com/20.0/.
Monadic Less Than Or Equal To Sign is not defined
Dyadic Less Than or Equal To Sign means
1 2 3 ≤ 4 2 ¯1
1 1 0
1 2 3 ≤ 2
1 1 0
NB: More recent documentation for Dyalog APL is available at https://docs.dyalog.com/20.0/.
Monadic Less Than Or Equal To Sign is not defined
1 2 3 ≤ 4 2 ¯1
1 1 0
1 2 3 ≤ 2
1 1 0