Here a cause is what explains why the relevant state occurs, and an effect is the state resulting from it.
When heating accounts for a rod’s expansion under controlled conditions, heating is the cause and expansion the effect. Inferring the expansion from heating illustrates a limmī direction; inferring heating from the expansion may illustrate an innī direction, provided alternative causes are addressed.
Reversing word order does not reverse causation. The real explanatory relationship determines the classification.