Cross-clue technique · Intermediate
Disjunction Resolution
The moment one branch of an either/or clue is disproved, the other branch becomes true.
Why it works
An either/or clue only leaves two possibilities open. Once the board independently rules one out, nothing else is left.
Trigger
An either/or clue where one of its two branches has just been eliminated by something unrelated.
Common mistake
Forgetting an either/or clue was ever recorded, and missing the moment its second branch gets forced.
Example
'Either Mina or Theo owns the turtle' plus a later clue ruling out Mina/turtle directly forces Theo/turtle, with no further reasoning needed.