Self-pin/self-unpin
In the course of the solution, a piece is first self-pinned, then self-unpinned again.
See also: Pin/unpin; Pin/self-unpin; Self-pin/unpin.
Lois, Jorge Joaquín
Kapros, Jorge Marcelo
feenschach, 1983
1st Prize
h#3 b) wPd3→h4
(4+10)
a) 1.Kf5
Ka2
2.Re5
Sd5
3.Qg5
Sg7#
b) 1.Kf6
Kxa4
2.Be5
Sd4
3.Qe7
Sh5#