On the Subject of Q.E.D.s

Quaduplets Elusively Detectable

This module has sixteen cards, each with four features:

1. The card's shape
2. The card's symbol's shape
3. The card's symbol's fill
4. The card's highlighted color and the card's symbol's highlighted color

A Q.E.D. consists of four elements, where for each feature individually, one of three conditions is true:

1. All four elements are different with respect to the feature.
2. Two pairs of two elements each are identical with respect to the feature.
3. All four elements are identical with respect to the feature.

A S.E.T. consists of three elements, where for each feature individually, one of two conditions is true:

1. All three elements are different with respect to the feature.
2. All three elements are identical with respect to the feature.

Locate a S.E.T. of Q.E.D.s of cards. The features of a Q.E.D. consist of which condition is true for each card element. No Q.E.D. can repeat a card already present in a Q.E.D. Select all four cards in one Q.E.D., then all four cards in a second Q.E.D, then all four cards in the the third Q.E.D.

Once an entire S.E.T. has been selected, the module will solve. Selecting four cards which do not form a Q.E.D. or three Q.E.D.s which do not form a S.E.T. will result in a strike.