+(macro
+ (adjust-tone
+ (set TT @-1)
+ (delete @-)
+ (cond ((| (= T ?ꫀ) (= T ?ꫂ)) (delete @-) (move @>))
+ ((> T 0) (move M) (delete @-) (move @>)))
+ (set T TT)
+ (cond ((| (= T ?ꫀ) (= T ?ꫂ)) (insert T))
+ ((> T 0) (move M) (insert T) (mark M) (move @>)))))
+