* algebra/coerce.spad.pamphlet (CoercibleFrom): New.

	(ConvertibleFrom): Likewise.
	(RetractableTo): Use it.
	* algebra/Makefile.pamphlet (axiom_algebra_layer_0): Include
	KRCFROM and KVTFROM.
	* share/algebra/: Update databases.

1 files changed, 62 insertions, 6 deletions

diff --git a/src/algebra/coerce.spad.pamphlet b/src/algebra/coerce.spad.pamphlet
index f270bba6..8176377a 100644
--- a/src/algebra/coerce.spad.pamphlet
+++ b/src/algebra/coerce.spad.pamphlet
@@ -1,15 +1,20 @@
 \documentclass{article}
 \usepackage{axiom}
-\begin{document}
+
 \title{\$SPAD/src/algebra coerce.spad}
 \author{Richard Jenks, Manuel Bronstein, Gabriel Dos Reis}
+
+
+\begin{document}
+
 \maketitle
 \begin{abstract}
 \end{abstract}
-\eject
 \tableofcontents
 \eject
+
 \section{category TYPE Type}
+
 <<category TYPE Type>>=
 )abbrev category TYPE Type
 ++ The new fundamental Type (keeping Object for 1.5 as well)
@@ -39,6 +44,7 @@ UnionType(): Category == with nil
 
 
 \section{category KOERCE CoercibleTo}
+
 <<category KOERCE CoercibleTo>>=
 )abbrev category KOERCE CoercibleTo
 ++ Category for coerce
@@ -53,7 +59,28 @@ CoercibleTo(S:Type): Category == with
       ++ coerce(a) transforms a into an element of S.
 
 @
+
+\section{category KRCFROM CoercibleFrom}
+
+<<category KRCFROM CoercibleFrom>>=
+)abbrev category KRCFROM CoercibleFrom
+++ Author: Gabriel Dos Reis
+++ Date Create: November 19, 2008
+++ Date Last Modified: November 19, 2008
+++ See Also: CoercibleTo
+++ Description:
+++   A is coercible from B iff any element of domain B can be
+++   automically converted into an element of domain B.  In symbols
+++      A has CoercibleFrom B   <=>  B has CoercibleTo A
+CoercibleFrom(S: Type): Category == with
+  coerce: S -> %
+    ++ coerce(s) transforms `s' into an element of `%'.
+
+@
+
+
 \section{category KONVERT ConvertibleTo}
+
 <<category KONVERT ConvertibleTo>>=
 )abbrev category KONVERT ConvertibleTo
 ++ Category for convert
@@ -69,20 +96,43 @@ ConvertibleTo(S:Type): Category == with
       ++ convert(a) transforms a into an element of S.
 
 @
+
+\section{category KVTFROM ConvertibleFrom}
+
+<<category KVTFROM ConvertibleFrom>>=
+)abbrev category KVTFROM ConvertibleFrom
+++ Author: Gabriel Dos Reis
+++ Date Create: November 19, 2008
+++ Date Last Modified: November 19, 2008
+++ See Also: ConvertibleTo
+++ Description:
+++   A is convertible from B iff any element of domain B can be
+++   explicitly converted into an element of domain B.  In symbols
+++      A has ConvertibleFrom B   <=>  B has ConvertibleTo A
+ConvertibleFrom(S: Type): Category == with
+  convert: S -> %
+    ++ convert(s) transforms `s' into an element of `%'.
+
+@
+
+
+
+
+
 \section{category RETRACT RetractableTo}
+
 <<category RETRACT RetractableTo>>=
 )abbrev category RETRACT RetractableTo
 ++ Category for retract
 ++ Author: ???
 ++ Date Created: ???
-++ Date Last Updated: 14 May 1991
+++ Date Last Updated: November 19, 2008
+++ Related Constructor: CoercibleFrom
 ++ Description:
 ++ A is retractable to B means that some elementsif A can be converted
 ++ into elements of B and any element of B can be converted into an
 ++ element of A.
-RetractableTo(S: Type): Category == with
-    coerce:       S -> %
-      ++ coerce(a) transforms a into an element of %.
+RetractableTo(S: Type): Category == CoercibleFrom S with
     retractIfCan: % -> Union(S,"failed")
       ++ retractIfCan(a) transforms a into an element of S if possible.
       ++ Returns "failed" if a cannot be made into an element of S.
@@ -95,10 +145,14 @@ RetractableTo(S: Type): Category == with
       u
 
 @
+
 \section{License}
+
 <<license>>=
 --Copyright (c) 1991-2002, The Numerical ALgorithms Group Ltd.
 --All rights reserved.
+--Copyright (C) 2007-2008, Gabriel Dos Reis.
+--All rights reserved.
 --
 --Redistribution and use in source and binary forms, with or without
 --modification, are permitted provided that the following conditions are
@@ -134,7 +188,9 @@ RetractableTo(S: Type): Category == with
 <<category TYPE Type>>
 <<category UTYPE UnionType>>
 <<category KOERCE CoercibleTo>>
+<<category KRCFROM CoercibleFrom>>
 <<category KONVERT ConvertibleTo>>
+<<category KVTFROM ConvertibleFrom>>
 <<category RETRACT RetractableTo>>
 @
 \eject