A shunt is this kind of micro-ladder.
It is an elementary tactic, but it may not be so easy to see several moves away.
Here it means 'hitting something that immediately hits something else'. That is, is atari and hits the white stones into .
When the position is shown explicitly as above, this is just a one-move reading problem; and shunt applies simply to . But it could possibly mean a three-move problem like - White - .
Shunting is done on the railways when carriages or goods trucks are pushed around by an engine, to sort out rolling stock onto the correct track or create long trains. Also, a shunt can occur when car A hits car B from behind, and then car B hits car C just on momentum.
- /Discussion, which includes linguistic discussion