Поменять местами в списке 1 и M-ый элементы.

include "312.inc"
 
Domains
List=integer*
Predicates
 
 nondeterm Do(list, integer,integer,integer)
 %Zamena()
Goal
Readterm(list,L),L=[H|T],readint(M), do(L,M,1, E).
 
Clauses
Do([H|T],M,Q,E):- M=Q,E=H;
                  Q1=Q+1,write (Q1),nl,!, Do(T,M,Q1,E).

Domains
list=integer*
 
Predicates
nondeterm do(list, integer,integer,list)
nondeterm do(list, integer,list)
 
Goal
readterm(list,L),readint(M), do(L,M,Ans).
 
Clauses
do(L,1,L):-!.
do([H|Tail],M,Ans):-do(Tail,M,H,Ans).
 
do([H|Tail],2,E,[H,E|Tail]):-!.
do([H|Tail],N,E,[H1,H|Tail1]):-N1=N-1,do(Tail,N1,E,[H1|Tail1]).

main([H|Tail],M,L1):-
    zamena(Tail,2,M,H,El,L),
    zamena1(L,El,L1).
    
 
zamena([H|Tail],I,M,First,El,[H|Tail1]):-
    I<M,
    I1 is I+1,
    zamena(Tail,I1,M,First,El,Tail1).
zamena([H|Tail],I,M,First,H,[First|Tail1]):-
    I=:=M,
    I1 is I+1,
    zamena(Tail1,I1,M,First,H,Tail1).
zamena([H|Tail],_,_,_,_,[H|Tail1]):-
       zamena(Tail,_,_,_,_,Tail1).
zamena([],_,_,_,El,[]).
 
zamena1([H|Tail],El,[El|Tail]).

do(L,1,L):-!.
do([H|Tail],M,Ans):-do(Tail,M,H,Ans).
 
do([H|Tail],2,E,[H,E|Tail]):-!.
do([H|Tail],N,E,[H1,H|Tail1]):-N1 is N-1,%вместо N1=N-1,
     do(Tail,N1,E,[H1|Tail1]).

main([H|Tail],M,[El|L1]):-
    zamena(Tail,2,M,H,El,L1).
 
zamena([X|Tail],I,M,First,El,[X|Tail1]):-
    I<M,
    I1 is I+1,
    zamena(Tail,I1,M,First,El,Tail1).
zamena([X|Tail],M,M,First,X,[First|Tail]).