PROLOG Program to Find Fibonacci Series

predicates
run(integer, integer)
go
database
f(integer, real)
clauses
go:- assert(f,(1, 0)),
assert(f(2,1)), readint(N),
N>2, run(2,N).
go:-
write("Enter a positive number than 2")'
run(I, N)if
I<N, I3=I+1,
I1=I3-1,
I2=I3-2,
f(I1,A),
f(I2,B), C=A+B
assert(f(I3,C)), run(I3, N).
run(N,N) if f(N,R),
write("Fibonacci Series", N, "is=", R), n1.