select_dict/3

Availability:built-in

[semidet]select_dict(+Select, +From, -Rest)

True when the tags of Select and From have been unified, all keys in Select appear in From and the corresponding values have been unified. The key-value pairs of From that do not appear in Select are used to form an anonymous dict, which is unified with Rest. For example:

?- select_dict(P{x:0, y:Y}, point{x:0, y:1, z:2}, R).
P = point,
Y = 1,
R = _{z:2}.

See also :</2 to ignore Rest and >:</2 for a symmetric partial unification of two dicts.