diff --git a/fz/paccs/output.pl b/fz/paccs/output.pl
index edcd0e9..be6902f 100644
--- a/fz/paccs/output.pl
+++ b/fz/paccs/output.pl
@@ -17,10 +17,12 @@ cg_emit(PS, VS, CS, G, ST) -->
 
 % == DCGs for code generation =================================================
 
+
 % -- predicates ---------------------------------------------------------------
 
 cg_preds(_PS, _ST) --> [].
 
+
 % -- variables ----------------------------------------------------------------
 
 cg_vars(OP,  [V|Vs], ST) --> cg_var(OP, V, ST), cg_vars(OP, Vs, ST).
@@ -71,12 +73,19 @@ cg_constant_list([C|Cs], PFX) -->
 
 cg_constant(lit(N,int)) --> { format_to_codes(S, "~w", [N]) }, S.
 
+
 % -- constraints --------------------------------------------------------------
 
-cg_constrs([C|Cs], ST) --> cg_constr(C, ST), cg_constrs(Cs, ST).
-cg_constrs([], _) --> [].
+cg_constrs([], _) --> {!}, [].
+cg_constrs(CS, ST) --> cg_coverage(CS, CR, ST), cg_constrs(CR, ST).
+
+% ++ cg_coverage(CI, CO, ST) [DCG]  - - - - - - - - - - - - - - - - - - - - - -
+%
+% emit an instruction which partly covers CI, leaving CO untreated
+
+cg_coverage([_C|CS], CS, _ST) --> [].	% FIXME: temporary
 
-cg_constr(_C, _ST) --> [].	% FIXME: temporary
+% cg_coverage(CI, CO, ST) --> [].
 
 % -- goal ---------------------------------------------------------------------
 
@@ -84,7 +93,8 @@ cg_goal(solve(satisfy,_), VS, ST) --> % FIXME: add minimize and maximize
     "\n",
     "  if (fd_solve()) {\n",
     cg_var_print(VS, ST, "    "),
-    "  }\n".
+    "  }\n",
+    "  fd_end();\n".
 
 cg_var_print([], _, _) --> [].
 cg_var_print([var(N,_,_,A)|Vs], ST, PFX) -->
--
libgit2 0.21.2