%Source: Ports of programs found in TPDB/C/AProVE_numeric
%query:test_fun(g,g).
% source: http://cl2-informatik.uibk.ac.at/mercurial.cgi/TPDB/file/72cccd64ec42/C/AProVE_numeric/svcomp_c.02.c

test_fun(X, Y) :- loop1(X, Y, 0).

loop1(X, Y, C) :- X >= 0, X1 is X + 1, Y1 is 1, loop2(X1, Y1, C).
loop1(X, Y, C) :- X < 0.

loop2(X, Y, C) :- X > Y, Y1 is Y + 1, C1 is C + 1, loop2(X, Y1, C1).
loop2(X, Y, C) :- X =< Y, X1 is X - 2, loop1(X1, Y, C).