prog.pl:16: warning: singleton variables [Root] for host_root/2
/home/g3yHfK/gplcSwWnmb.o: In function `predicate(host_root/2)':
(.text+0x3e): undefined reference to `predicate(is_prefix/1)'
/home/g3yHfK/gplcSwWnmb.o: In function `Lpred1_1':
(.text+0x6b): undefined reference to `predicate(is_prefix/1)'
/home/g3yHfK/gplcSwWnmb.o: In function `predicate(installed_correctly/2)':
(.text+0xab): undefined reference to `predicate(installed/2)'
/home/g3yHfK/gplcSwWnmb.o: In function `predicate(installed_correctly/2)':
(.text+0x115): undefined reference to `predicate(forall/2)'
/home/g3yHfK/gplcSwWnmb.o: In function `predicate(installed_completely/2)':
(.text+0x15b): undefined reference to `predicate(installed/2)'
/home/g3yHfK/gplcSwWnmb.o: In function `predicate(installed_completely/2)':
(.text+0x1ca): undefined reference to `predicate(forall/2)'
/home/g3yHfK/gplcSwWnmb.o: In function `predicate(installed_completely/2)':
(.text+0x234): undefined reference to `predicate(forall/2)'
/home/g3yHfK/gplcSwWnmb.o: In function `predicate(can_be_built/2)':
(.text+0x2ef): undefined reference to `predicate(forall/2)'
/home/g3yHfK/gplcSwWnmb.o: In function `predicate(can_be_built/2)':
(.text+0x359): undefined reference to `predicate(forall/2)'
/home/g3yHfK/gplcSwWnmb.o: In function `predicate(can_be_built_against/2)':
(.text+0x405): undefined reference to `predicate(forall/2)'
/home/g3yHfK/gplcSwWnmb.o:(.text+0x4b4): more undefined references to `predicate(forall/2)' follow
collect2: ld returned 1 exit status
compilation failed