Stage 4 of LOGOSGBITS: seven trials in immediate inference — moving from one claim to another in a single step. A claim can be turned around in three ways, and only one of them keeps the truth. Learn which, and no rearrangement can move you off a claim you have good reason to hold.
Each trial is locked until you clear the one before it. Every level scores out of 1000 — 600 for accuracy, 400 for speed — so speed alone can't clear the bar; you have to solve most problems, and quickly. Reach 650 to unlock the next.
You can form a converse, an inverse and a contrapositive, name which move has been made, and say which of them actually preserves the truth — including when a categorical claim may safely have its terms swapped and when it may not.