Quickly verify (and locate) the existence of a breach.

Used when a single instance is likely to occur and be important to detect quickly (in a sufficiently large integer vector).

Arguments

x	An integer vector.
a	A (single) integer. That which is to be compared.
gt, lt, eq	Booleans, whether or not the comparison is greater than, less than, or equal to. Only gt and lt are mutually exclusive.