From cbmvax!uunet!Think.COM!gls Mon Jul 8 15:31:43 1991 Return-Path: Date: Mon Jul 8 15:31:43 1991 Return-Path: From: Guy Steele Message-Id: <9107081845.AA12884@strident.think.com> To: cbmvax!snark.thyrsus.com!lojbab Cc: lojban-list@snark.thyrsus.com In-Reply-To: Bob LeChevalier's message of Mon, 8 Jul 91 02:14 EDT Subject: Jeff Prothero on elidable terminators issue from before LogFest Status: RO Prothero's note is very clear and provides a good framework for discussing the question, but it does not yet answer my objections. The strongest objection is this: while he has argued the possibility of parsing the augmented language by LALR(1) techniques, he has not provided an effective procedure for constructing the necessary tables. Therefore he has not addressed the question of how complex these tables must be compared to the tables for the unaugmented language. Indeed, his argument has not yet ruled out the possibility that the tables must be infinite in size! For he argues that the parser can implicitly regenerate "a]Bc" from "aBc"; but it must be able to do this for any string "a" such that "aBc" in not in the original language. There may be an infinite number of such strings "a". He has not yet shown that a finite number of table entries will be able to cover all the possible decisions to be made. I conjecture that in the general case a finite table will not suffice. My original arguments suggested that we ought to answer the question definitively for the specific case of Lojban, rather than merely handwaving. --Guy Steele