1.1 --- a/src/Tools/isac/ProgLang/Prog_Expr.thy	Thu Jun 10 17:06:32 2021 +0200
     1.2 +++ b/src/Tools/isac/ProgLang/Prog_Expr.thy	Fri Jun 11 11:49:34 2021 +0200
     1.3 @@ -527,7 +527,7 @@
     1.4  
     1.5  subsection \<open>extend rule-set for evaluating pre-conditions and program-expressions\<close>
     1.6  ML \<open>
     1.7 -val prog_expr = Rule_Set.append_rules "prog_expr" prog_expr [Rule.Eval ("Prog_Expr.rhs", Prog_Expr.eval_rhs "")];
     1.8 +val prog_expr = Rule_Set.append_rules "prog_expr" prog_expr [\<^rule_eval>\<open>Prog_Expr.rhs\<close> (Prog_Expr.eval_rhs "")];
     1.9  \<close> ML \<open>
    1.10  \<close> ML \<open>
    1.11  \<close>