Pushdown

Since indexed grammars are context-free grammars with pushdowns, the generalization of Thatcher's result shows that they generate the yields of the tree languages recognized by deterministic pushdown tree automata.

filter pushdown

predicate pushdown

Machine exercises with weight stacks, like pushdowns or pulldowns, are ideal for cranking out more than three drops because all you need to do is insert the pin in a higher (lighter) slot each time.

[T]he unfortunate few who suffer from it [ejaculatory anhedonia] are incapable of deriving any pleasure whatsoever from orgasms. They make a bit of mess while staring impassively into the middle distance, and that's it. Like the human equivalent of a pushdown soap-dispenser.

The containers we always use for those are the OXO ones that have the pushdown button, so I think it probably does stay fresher than flour in a paper bag, and in that way, it works.

This 30ml serum bottle has a pushdown release nozzle applicator.