is
True when this variable's values are spaced exactly one apart, which requires a granularity of exactly 1.0.
Note that this is STRICTER than the usual meaning of "integer-ordered" in the discrete-optimization-via-simulation literature, where it is enough that the feasible values be integers. A variable with granularity 5.0 over the range 30 to 100 takes only integer values and is integer-ordered in that looser sense, but it is not unit-spaced and this property is false for it.
The distinction is not academic: the solvers that require this property step one unit along a coordinate at a time, in the variable's own units, so a coarser spacing would put every step between feasible values rather than on them.