diff -r dff64b2e7ec3 -r 2c4c0d93daa6 Quotient-Paper/document/root.tex --- a/Quotient-Paper/document/root.tex Thu Jun 10 13:37:32 2010 +0200 +++ b/Quotient-Paper/document/root.tex Fri Jun 11 14:04:58 2010 +0200 @@ -6,7 +6,8 @@ \usepackage{amsmath} \usepackage{amssymb} \usepackage{pdfsetup} - +\usepackage{tikz} +\usepackage{pgf} \urlstyle{rm} \isabellestyle{it} @@ -24,19 +25,18 @@ \maketitle \begin{abstract} -Higher-order logic (HOL), used in a number of theorem provers, is based on a small -logic kernel, whose only mechanism for extension is the introduction of safe -definitions and non-empty types. Both extensions are often performed by -quotient constructions; for example finite sets are constructed by quotienting -lists, or integers by quotienting pairs of natural numbers. To ease the work -involved with quotient constructions, we re-implemented in Isabelle/HOL the -quotient package by Homeier. In doing so we extended his work in order to deal -with compositions of quotients. Also, we designed our quotient package so that -every step in a quotient construction can be performed separately and as a -result we were able to specify completely the procedure of lifting theorems from -the raw level to the quotient level. The importance to programming language -research is that many properties of programming languages are more convenient -to verify over $\alpha$-quotient terms, than over raw terms. +Higher-Order Logic (HOL) is based on a small logic kernel, whose only +mechanism for extension is the introduction of safe definitions and of +non-empty types. Both extensions are often performed in quotient +constructions. To ease the work involved with such quotient constructions, we +re-implemented in Isabelle/HOL the quotient package by Homeier. In doing so we +extended his work in order to deal with compositions of quotients. Also, we +designed our quotient package so that every step in a quotient construction +can be performed separately and as a result we were able to specify completely +the procedure of lifting theorems from the raw level to the quotient level. +The importance for programming language research is that many properties of +programming language calculi are easier to verify over $\alpha$-equated, or +$\alpha$-quotient, terms, than over ``raw'' terms. \end{abstract} % generated text of all theories