is_uexists : term -> bool

- SYNOPSIS
- Tests if a term is of the form `there exists a unique ...'
- DESCRIPTION
- If t has the form ?!x. p[x] (there exists a unique x such that p[x] then is_uexists t returns true, otherwise false.
- FAILURE CONDITIONS
- Never fails.
- SEE ALSO
- dest_uexists, is_exists, is_forall.