Paterson (poem) caught Williams' attention for its use, with a technical skill that seemed to rival Pound's in "The Cantos", of such diverse and seemingly prosaic materials as notes from a congressional investigation, an X-ray report and a physician's testimony on cross-examination. He wrote to fellow poet Louis Zukofsky, "I've begun to think about poetic form again. So much has to be thought out and written out there before we can have any solid criticism and consequently well-grounded work here." In 1944, Williams read a poem by Byron Vazakas in "Partisan Review" that would help lead him to solutions in form and
LL grammar generated by some "ε"-free LL("k") grammar. As allowing more tokens of lookahead makes the parser strictly more powerful, the languages that can be recognized with a LL("k") parser are a strict subset of the languages that can be recognized by a LL("k+n"), "n > 0" parser. This creates a strictly increasing sequence of sets: LL(0) ⊊ LL(1) ⊊ LL(2) ⊊ …. Since these are all DCFLs, a corollary is that for any fixed "k", there are DCFLs that cannot be recognized by a LL("k") parser. An LL parser is called an LL(*) parser if it is not restricted to a