From 55d128d9884acd0d1ecea0de342f7f9050215559 Mon Sep 17 00:00:00 2001 From: Adam Chlipala Date: Thu, 6 Jun 2024 07:52:32 -0400 Subject: [PATCH] Italicize a term on first use (thanks to Todd Morley for the suggestion) --- frap_book.tex | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/frap_book.tex b/frap_book.tex index 59523c4..5d8eeae 100644 --- a/frap_book.tex +++ b/frap_book.tex @@ -1181,7 +1181,7 @@ $$\begin{array}{rrcl} \underline{\textrm{Variables}} & p \\ \textrm{Formula} & \phi &::=& \top \mid \bot \mid \phi \land \phi \mid \phi \lor \phi \mid \underline{p \mid \phi \Rightarrow \phi} \end{array}$$ -Note how we add propositional variables $p$, which stand for unknown truth values. +Note how we add \emph{propositional variables} $p$, which stand for unknown truth values. What is fundamentally harder about modeling implication? We need to perform \emph{hypothetical reasoning}\index{hypothetical reasoning}, trying to prove a formula with other formulas available as known facts.