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 LL("m") grammar for some "m". A "ε"-free LL(1) grammar is also a SLR(1) grammar. A LL(1) grammar with symbols that have both empty and non-empty derivations is also a LALR(1) grammar. A LL(1) grammar with symbols that have only the empty derivation may or may not be LALR(1). LL grammars cannot have rules containing left recursion. Removing left recursion from a context-free grammar is always possible. However, the resulting grammar may be bigger, require more lookahead tokens than preferred to be an LL grammar, or not be an LL grammar at all. LL("k") grammars that are ε-free can be transformed