nullary_ho_func_error.m:026: In clause for predicate `main'/2:
nullary_ho_func_error.m:026:   in argument 1 of call to predicate
nullary_ho_func_error.m:026:   `io.print_line'/3:
nullary_ho_func_error.m:026:   in argument 1 of functor `apply_nullary_func/1':
nullary_ho_func_error.m:026:   type error in unification of argument
nullary_ho_func_error.m:026:   and constant `pi'.
nullary_ho_func_error.m:026:   argument has type
nullary_ho_func_error.m:026:     (func) = T,
nullary_ho_func_error.m:026:   constant `pi' has type
nullary_ho_func_error.m:026:     float.
nullary_ho_func_error.m:026:   The partial type assignment was:
nullary_ho_func_error.m:026:     STATE_VARIABLE_IO_0_4: io.state
nullary_ho_func_error.m:026:     STATE_VARIABLE_IO_5: io.state
nullary_ho_func_error.m:026:     V_6: string
nullary_ho_func_error.m:026:     STATE_VARIABLE_IO_7_7: io.state
nullary_ho_func_error.m:026:     V_8: T
nullary_ho_func_error.m:026:     V_10: ((func) = T)