For the photochemical reaction of the [2+2] cyclodimerization trans-cinnamic acid; draw the structures of the six diastereomers of the truxinic acids and the five diasteromers of the truxillic acids, clearly showing the photochemistry. Present only one enantiomer for any chiral dimers, but bear in mind that in the photodimerization, chiral dimers are obtained as racemates