rules = [Rls_ diff_rules,

 	 rules = [Rls_ diff_rules,

 		  Rls_ norm_Poly

 		  Rls_ norm_Poly

 		  ],

 		  ],

 	 scr = EmptyScr};

 	 scr = EmptyScr};

 ruleset' := 

 ruleset' := 

 	    [("diff_rules", prep_rls norm_diff),

 	    [("diff_rules", prep_rls norm_diff),

 	     ("norm_diff", prep_rls norm_diff),

 	     ("norm_diff", prep_rls norm_diff),

 	     ("diff_conv", prep_rls diff_conv),

 	     ("diff_conv", prep_rls diff_conv),

 	     ("diff_sym_conv", prep_rls diff_sym_conv)

 	     ("diff_sym_conv", prep_rls diff_sym_conv)

 	     ]);

 	     ]);