remove now unnecessary dependencies, correct ordering of ! in (;)/3

src/main.rs

@@ -13,7 +13,6 @@ extern crate prolog_parser;
 #[macro_use]
 extern crate ref_thread_local;
 
-use git_version::git_version;
 use nix::sys::signal;
 
 mod prolog;
@@ -22,7 +21,6 @@ use crate::prolog::machine::*;
 use crate::prolog::machine::streams::*;
 use crate::prolog::read::*;
 
-use std::env;
 use std::sync::atomic::Ordering;
 
 extern fn handle_sigint(signal: libc::c_int) {

src/prolog/lib/builtins.pl

@@ -233,9 +233,13 @@ semicolon_compound_selector(';'(G2, G3), G4, B) :-
 
 :- non_counted_backtracking (;)/3.
 ;(G1, G4, B) :-
-    compound(G1),
-	semicolon_compound_selector(G1, G4, B),
-    !.
+    ( (  G1 = (_ -> _)
+      ;  G1 = (_ , _)
+      ;  G1 = (_ ; _) 
+      ) ->
+      !,
+      semicolon_compound_selector(G1, G4, B)
+    ).
 ;(G1, G2, B) :-
     G1 == !, !, '$set_cp'(B), call(G2).
 ;(G1, G2, B) :-
@@ -1144,4 +1148,3 @@ parse_stream_options_(eof_action(Action), eof_action-Action) :-
     ).
 parse_stream_options_(E, _) :-
     throw(error(domain_error(stream_option, E), _)). % 8.11.5.3i)
-