A ≼ B     1 if and only if A precedes (or is equal to) B in the ordering

   3 1 4 1 5 9 ≼ 7 ¯1.5 
1
   3 1 4 1 5 9 ≼ '314159'  
0
   '314159' ≼ 3 1 4 1 5 9 
1
   '314159' ≼ 7 ¯1.5
1

   ∘.≼ ⍨ 2j¯1 2 2j3 
1 1 1
0 1 1
0 0 1

)copy dfns le
le← {(⍳2) ≡ ⍋ ⍺ ⍵}