Thun/docs/reference/app1.md

apply one

## app1 "apply one" Combinator Given a quoted program on TOS and anything as the second stack item run the program without disturbing the stack and replace the two args with the first result of the program. ... x [Q] app1

   ... [x ...] [Q] infra first

This is the same effect as the unary combinator.

Definition

nullary popd

Discussion

Just a specialization of nullary really. Its parallelizable cousins are more useful.

Crosslinks

app2 app3 appN unary