I can cheat, by hiding the assignment in another function.
AAr =: 1 : '(5!:1 < ''a'') a =. 1 : m'
'u u`:6('',(5!:5<''u''),'')`:6 y' AAr
<(<,':'),<(<(,'0');1),<(,'0');,:'u u`:6('',(5!:5<''u''),'')`:6 y' (1 : 'u
u`:6('',(5!:5<''u''),'')`:6 y')
this is not the same as Y though.
but this is,
YA
Some authors regard functional programming as programming without any
assignments.
The wicked tacit fixed version of Y has no assignments whatsoever but it is
produced and it works by means of non-standard J code. I could alter
slightly the non-tacit version,
Y=. '(5!:1<''v'')v=. 1 : (''u u`:
