New poems from old by substitution

     Just as we get new numbers by substitution of new inputs into old formulas -- such as x² or sinx -- we may get new poems from old ones into which we substitute new words. For example, take a poem and, for each of the nouns in the poem, substitute for it the noun that occurs 7 positions later in a given dictionary. This N+7 rule is one of the inventions of the French group of writers and mathematicians known as the Oulipo.  (For more information, see postings from 25 March 2010, 23 August 2010, 15 November 2010 and 3 January 2011.)