Are conjunctions unassignable?

[ArrayMac227]

opp←{⍺ ⍺⍺ ⍵⍵ ⍵}
tfuu←opp
SYNTAX ERROR
tfuu←opp
∧

⍝ How do I assign opp?

[Roger|Dyalog]

In current Dyalog APL, a dyadic d-operator may be named using ←. No other dyadic operator may not so named. For example,

      rank←⍤
SYNTAX ERROR
      rank←⍤
          ∧

[Phil Last]

... a dyadic d-operator may be named using ←. ...

but not reassigned as Randy discovered

... tfuu←opp ...

[Phil Last]

You can't create a reference to it

      )clear
clear ws
      opp←{⍺←⊢ ⋄ (⍺ ⍺⍺ ⍵)⍵⍵ ⍵}
      )ns s
#.s
      s.op←opp
SYNTAX ERROR
      s.op←opp
             ∧

either thither ↑ or thence ↓

      )cs s
#.s
      op←#.opp
SYNTAX ERROR
      op←#.opp
            ^

but you can call it directly with its fully qualified name

      2 + #.opp × 3
15

or you can create a cover that does that for you

      op←{⍺←⊢ ⋄ ⍺ ⍺⍺ #.opp ⍵⍵ ⍵}
      2 + op × 3
15