Ошибка Free variable in expression 707 - Prolog

domains 
    S=real
    D=real*
    file=lab5
predicates
    tabl
    vvod(S,S,S,D)
    cikle(S,S,S,S)
    cikleterm(S,S,S,D)
    M(S,S)
    vivod
goal
    tabl.
clauses 
    tabl:-
        vvod(X0,Hx,Xn,D),
        X=X0,
        openwrite(lab5,"Vivod.txt"),
        writedevice(lab5),
        nl,writef("Tablica znacheniy"),
        nl,writef("   X        Y          obl"),
        nl,cikleterm(X,Hx,Xn,D),
        closefile(lab5),
        openread(lab5,"Vivod.txt"),
        vivod,
        closefile(lab5).
    vvod(X0,Hx,Xn,[Y|Yn]):-
        nl,writef("Vvedite: :"),nl,
        write("X0= "),readreal(X0),
        write("Hx= "),readreal(Hx),
        write("Xn= "),readreal(Xn),
        write("Y[-2...2] "),readterm(D,[Y|Yn]).
    cikleterm(X,Hx,Xn,[Y|Yn]):-
        cikle(X,Hx,Xn,Y),
        cikleterm(X,Hx,Xn,Yn),
        cikle(_,_,_,_).
    cikle(X,Hx,Xn,Y):-
        X<=Xn,!,
        M(X,Y),
        X1=X+Hx,
        cikle(X1,Hx,Xn,Y),
        cikle(_,_,_,_).
    cikle(_,_,_,_):-
        writef("_______________________").
    M(X,Y):-
        X<=0,!,
        Y>=-1,!,
        Y<=X,!,
        writef("%-7.2 %-7.2",X,Y),
        writef("v obl 1"),!,nl.
    M(X,Y):-
        Y<=X,
        X<=1,
        Y>=0,
        writef("%-7.2 %-7.2",X,Y),
        writef("v obl 2"),!,nl.
    M(X,Y):-
        writef("%-7.2 %-7.2", X, Y),
        write("ne popal"),nl.
    vivod:-
        readdevice(lab5),
        not(eof(lab5)),
        readln(Y),
        writedevice(screen),
        write(Y),nl.
                vivod.