Self Reference | $: _ _ _ |
$: denotes the longest verb that contains it. For example:1:`(] * $:@<:)@.* 5 120In the foregoing expression, the agenda (@.) chooses the verb ] * $:@<: as long as the argument (reduced by one each time by the application of the decrement) remains non-zero. When the argument becomes zero, the result of the right argument of @. is zero, and the constant function 1: is chosen. If $:@ were omitted from the expression, it would execute once only as follows: 1:`(] * <:)@.* 5 20The inclusion of self-reference ensures that the entire function is re-executed after decrementing the argument. v f. will not fix any part of v that contains $: . |