CLPFDライブラリ読み込んでるけど使ってなかった…
:-use_module(library(clpfd)).
adding(1,0):-!.
adding(Idx,Sum):-
(Idx mod 3 =:= 0 ; Idx mod 5 =:= 0),
!,
Idx1 is Idx - 1,
adding(Idx1,Sum1),
Sum is Sum1 + Idx.
adding(Idx,Sum):-
!,
Idx1 is Idx - 1,
adding(Idx1,Sum).
%実行結果
%[1] 2 ?- adding(999,R).
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