Y may be any array. R is a simple character matrix which appears the same as the default display of Y. If Y contains control characters from ⎕TC, they will be resolved.
Examples
A←⎕FMT '∩' ,⎕TC[1],'∘' ⍴A 1 1 A ⍝ A←⎕VR 'FOO' A ∇ R←FOO [1] R←10 ∇ ⍴A 31 B←⎕FMT A B ∇ R←FOO [1] R←10 ∇ ⍴B 3 12