author paulson Fri Sep 26 11:04:21 2003 +0200 (2003-09-26) changeset 14209 180cd69a5dbb parent 14208 144f45277d5a child 14210 69e48401da98
tweak
     1.1 --- a/doc-src/Logics/syntax.tex	Fri Sep 26 10:34:57 2003 +0200
1.2 +++ b/doc-src/Logics/syntax.tex	Fri Sep 26 11:04:21 2003 +0200
1.3 @@ -36,9 +36,9 @@
1.4  syntax $\forall x.t$ to mean $All(\lambda x.t)$.  We can also write $\forall 1.5 x@1\ldots x@m.t$ to abbreviate $\forall x@1. \ldots \forall x@m.t$; this is
1.6  possible for any constant provided that $\tau$ and $\tau'$ are the same type.
1.7 -HOL's description operator $\varepsilon x.P\,x$ has type $(\alpha\To 1.8 -bool)\To\alpha$ and can bind only one variable, except when $\alpha$ is
1.9 -$bool$.  ZF's bounded quantifier $\forall x\in A.P(x)$ cannot be declared as a
1.10 +The Hilbert description operator $\varepsilon x.P\,x$ has type $(\alpha\To 1.11 +bool)\To\alpha$ and normally binds only one variable.
1.12 +ZF's bounded quantifier $\forall x\in A.P(x)$ cannot be declared as a
1.13  binder because it has type $[i, i\To o]\To o$.  The syntax for binders allows
1.14  type constraints on bound variables, as in
1.15  $\forall (x{::}\alpha) \; (y{::}\beta) \; z{::}\gamma. Q(x,y,z)$