ParticleBasic presentation hereInterpretive point
إِنْNo commitment to occurrenceLeaves the condition open
إِذَاOccurrence presented as assuredFrames the event as expected
لَوْMentioned, not systematically defined in this passageSignals another type of conditional expression
These are baseline meanings rather than mechanical descriptions of every occurrence. In can still occur with a known or impossible proposition, but this does not erase its contrast with idha.
Analysis must consider the condition’s factual status, the speaker’s rhetorical purpose, and the surrounding passage.