Conjunction, signaled by A, indicates that both of two items are said to be true. In a truth-table description of this we have the pattern
P Q || PQA
T T..........T
T F..........F
F T..........F
F F..........F

Various sentences express this basic relationship. For example, if we use a code in which P represents the idea that Jane passes and Q the idea that she studies, the sentence "Jane both studies and passes" would be either PQA or QPA. We could also have QPNA for "Jane passed but she didn't study" or QNPNA for "Jane will not pass because she has not studied." Note that the contrast or the notion of cause and effect present in the English sentences does not carry over into differences of symbolism any more than does a difference in tense. Also note that A is both commutative and associative: PQARA, QPARA, and RPQAA are equivalent strings (the columns for the final A are identical in the truth tables for the three strings).

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