Nowadays this fails with a typed exception X::Sequence::Deduction $ ./perl6 -e 'say 1, 2, 6 ... *' ===SORRY!=== Unable to deduce arithmetic or geometric sequence from 1,2,6 (or did you really mean '..'?)
$ ./perl6 -e 'say 1, 2, 6 ... 10' ===SORRY!=== Unable to deduce arithmetic or geometric sequence from 1,2,6 (or did you really mean '..'?) $ ./perl6 -e 'say ~(1, 2, 6 ... *)[10]' ===SORRY!=== Unable to deduce arithmetic or geometric sequence from 1,2,6 (or did you really mean '..'?) That looks fine to me. If no one objects I'll add a test for this and close the ticket.