Diaeresis is a Monadic operator with an ambivalent operand
Operator Diaeresis means
Each (with monadic operand) or Each (with dyadic operand)
⊃¨ 1 2 3 'ABC' (9 8 7)
1 2 3 A 9
+/¨ (1 2 3 4)(5 6 7)
10 18
3 ↑¨ 1 2 (3 4) 'V'
┌─────┬─────┬─────┬───┐
│1 0 0│2 0 0│3 4 0│V │
└─────┴─────┴─────┴───┘
1 2 3 ,¨ 99
┌────┬────┬────┐
│1 99│2 99│3 99│
└────┴────┴────┘