sub infix:<list_vals> {  ($^n ... 0) Z/ 1 .. $^p }
say 10 list_vals 3;    # -> (10 4.5 2.666667)
sub infix:<choose> { [*] ($^n ... 0) Z/ 1 .. $^p }
say 10 choose 3;       # -> 120 (rat)