"d" -> "c"-
~"d" -> "c"+
"present.j" -> "present.k"-
~"present.j" -> "present.k"+
"present.k" -> "present.l"-
~"present.k" -> "present.l"+
@ "c" iscomb
@ "b" iscomb
@ "present.l" iscomb
= "d" "present.P.a"
= "c" "present.P.b"
= "present.j" "present.Q.a"
= "present.k" "present.Q.b"
= "present.k" "present.R.a"
= "present.l" "present.R.b"
= "d" "present.w"
= "c" "present.x"
= "b" "present.y"
= "a" "present.z"
