+ndefinition xor_b8 ≝ fop2_cn ? xor_ex.
+
+(* operatore Most Significant Bit *)
+ndefinition getMSB_b8 ≝ getOPH_cn ? getMSB_ex.
+ndefinition setMSB_b8 ≝ setOPH_cn ? setMSB_ex.
+
+(* operatore Least Significant Bit *)
+ndefinition getLSB_b8 ≝ getOPL_cn ? getLSB_ex.
+ndefinition setLSB_b8 ≝ setOPL_cn ? setLSB_ex.
+
+(* operatore estensione unsigned *)
+ndefinition extu_b8 ≝ λe2.〈x0,e2〉.
+
+(* operatore estensione signed *)
+ndefinition exts_b8 ≝
+λe2.〈(match getMSB_ex e2 with
+ [ true ⇒ xF | false ⇒ x0 ]),e2〉.