Sentence:  Imagine, first, two players who engage in a game of <WSD>canasta</WSD> according to a standard set of rules....We may imagine, however, that at a certain moment the two <WSD>canasta</WSD> players cease to play <WSD>canasta</WSD> and start a discussion of the rules. 
Meaning of the word marked with <WSD> tags:  A card game similar to rummy and played using two packs, where the object is to meld groups of the same rank.