* algebra/catdef.spad.pamphlet (SemiRing): New category.

3 files changed, 24 insertions, 3 deletions

diff --git a/src/algebra/Makefile.in b/src/algebra/Makefile.in
index 0852a79b..5ba7f1f3 100644
--- a/src/algebra/Makefile.in
+++ b/src/algebra/Makefile.in
@@ -110,7 +110,7 @@ oa_strap_0_sources = \
 	PROPLOG BOOLE LOGIC \
 	ABELGRP LLINSET RLINSET LINSET CABMON ABELMON ABELSG \
 	SGROUP MONOID OAMON OAMONS OASGP OCAMON OAGROUP \
-	RNG RING ORDRING LMODULE RMODULE BMODULE \
+	RNG SRING RING ORDRING LMODULE RMODULE BMODULE \
 	COMRING ENTIRER ALGEBRA MODULE DIVRING FIELD \
 	DIFFSPC DIFFDOM DIFRING LINEXP PATMAB CFCAT REAL \
 	INTDOM GCDDOM PID UFD OINTDOM INS OM \
@@ -170,6 +170,7 @@ strap-0/LMODULE.$(FASLEXT): strap-0/ABELGRP.$(FASLEXT) \
 	strap-0/LLINSET.$(FASLEXT)
 strap-0/RMODULE.$(FASLEXT): strap-0/ABELGRP.$(FASLEXT) \
 	strap-0/RLINSET.$(FASLEXT)
+strap-0/SRING.$(FASLEXT): strap-0/ABELMON.$(FASLEXT) strap-0/MONOID.$(FASLEXT)
 strap-0/RING.$(FASLEXT): strap-0/RNG.$(FASLEXT) strap-0/MONOID.$(FASLEXT) \
 	strap-0/LMODULE.$(FASLEXT) strap-0/KRCFROM.$(FASLEXT)
 strap-0/COMRING.$(FASLEXT): strap-0/RING.$(FASLEXT) strap-0/BMODULE.$(FASLEXT)
@@ -852,7 +853,7 @@ axiom_algebra_layer_0 = \
   LINEXP   PATMAB   REAL     CHARZ    LOGIC    LOGIC-   \
   RTVALUE  SYSPTR   PDDOM    PDDOM-   PDSPC    PDSPC-   \
   DSEXT    DSEXT-   ORDTYPE  ORDTYPE- ORDSTRCT          \
-  BOOLE    BOOLE-   REF      ALIST    PRIMARR  
+  BOOLE    BOOLE-   REF      ALIST    PRIMARR  SRING
 
 axiom_algebra_layer_0_nrlibs = \
 	$(addsuffix .NRLIB/code.$(FASLEXT),$(axiom_algebra_layer_0))
@@ -878,6 +879,7 @@ $(OUT)/MAYBE.$(FASLEXT): $(OUT)/KOERCE.$(FASLEXT) $(OUT)/RETRACT.$(FASLEXT)
 
 $(OUT)/BYTEORD.$(FASLEXT): $(OUT)/SETCAT.$(FASLEXT)
 
+$(OUT)/SRING.$(FASLEXT): $(OUT)/ABELMON.$(FASLEXT) $(OUT)/MONOID.$(FASLEXT)
 $(OUT)/RING.$(FASLEXT): $(OUT)/RNG.$(FASLEXT) $(OUT)/MONOID.$(FASLEXT) \
 	$(OUT)/LMODULE.$(FASLEXT) $(OUT)/KOERCE.$(FASLEXT)
 $(OUT)/MONOID.$(FASLEXT): $(OUT)/SGROUP.$(FASLEXT)
diff --git a/src/algebra/catdef.spad.pamphlet b/src/algebra/catdef.spad.pamphlet
index f4447776..fe745809 100644
--- a/src/algebra/catdef.spad.pamphlet
+++ b/src/algebra/catdef.spad.pamphlet
@@ -224,7 +224,7 @@ BasicType(): Category == Type with
       ~=: (%,%) -> Boolean   ++ x~=y tests if x and y are not equal.
       before?: (%,%) -> Boolean
         ++ \spad{before?(x,y)} holds if the system representation
-        ++ of \spad{x} is comes before that of \spad{y} in a
+        ++ of \spad{x} comes before that of \spad{y} in a
         ++ an implementation defined manner.
    add
       x = y == not before?(x,y) and not before?(y,x)
@@ -1796,6 +1796,24 @@ RightModule(R:Rng):Category == Join(AbelianGroup, RightLinearSet R)
 
 @
 
+\section{category SRING SemiRing}
+<<category SRING SemiRing>>=
+)abbrev category SRING SemiRing
+++ Author: Gabriel Dos Reis
+++ Date Created: March 7, 2011
+++ Date Last Modified: March 7, 2011
+++ Description:
+++   The category of all semiring structures, e.g. triples (D,+,*)
+++   such that (D,+) is an Abelian monoid and (D,*) is a monoid
+++   with the following laws:
+++ Axioms:
+++    a * (b + c) = (a * b) + (a * c)
+++    (b + c) * a = (b * a) + (c * a)
+++    0 * a = 0
+++    a * 0 = 0
+SemiRing(): Category == Join(AbelianMonoid,Monoid)
+@
+
 \section{category RING Ring}
 <<category RING Ring>>=
 )abbrev category RING Ring
diff --git a/src/algebra/exposed.lsp.pamphlet b/src/algebra/exposed.lsp.pamphlet
index 3acfbcfe..ffc816cf 100644
--- a/src/algebra/exposed.lsp.pamphlet
+++ b/src/algebra/exposed.lsp.pamphlet
@@ -782,6 +782,7 @@
   (|SegmentCategory| . SEGCAT)
   (|SegmentExpansionCategory| . SEGXCAT)
   (|SemiGroup| . SGROUP)
+  (|SemiRing| . SRING)
   (|SetAggregate| . SETAGG)
   (|SetCategory| . SETCAT)
   (|SExpressionCategory| . SEXCAT)