When writing code that needs to do predicate dispatch (such as code analysis libraries), it's quite common to need an `invoke` function for a pattern that looks like:

This is definitely expressible without `invoke`, but the `condp invoke` pattern reads quite nicely.

Additionally `invoke` is also useful in the cases where one has a sliding window of functions and values, for patterns like:

Patch: 0001-CLJ-2342-add-invoke.patch