If Var is a number, Domain will be unified with that number.
If Var is a real IC variable, Domain will be unified with the term Lo..Hi where Lo and Hi are floats corresponding to the current lower and upper bounds of Var, respectively.
If Var is an integer IC variable with no holes in its domain, Domain will be unified with the term Lo..Hi where Lo and Hi are integers corresponding to the current lower and upper bounds of Var, respectively.
If Var is an integer IC variable with holes in its domain, Domain will be unified with an ordered list of integers and/or terms Lo..Hi where Lo and Hi are integers; in this case the elements of the domain of Var are exactly those integers appearing directly in the list or falling within any of the intervals Lo..Hi.