- — Negate / Subtract

-Y negates. Pervasive.

-3                ⍝ ¯3

X-Y subtracts. Pervasive.

10-1 2 3          ⍝ 9 8 7

Characters shift by code point. Character differences are exact integers.

'd'-3             ⍝ 'a'
'd'-'a'           ⍝ 3ₓ

¯ marks negative literals.