Add \triple for a three-tuple of things, (a,b,c).

[mjotex.git] / mjo-common.tex

diff --git a/mjo-common.tex b/mjo-common.tex
index e19d7883e6d9a7c70a5865d314cc9dabf1762f46..efa10a26045d9f199bd3bdb1f8c9f5ec97c1cb19 100644 (file)
--- a/mjo-common.tex
+++ b/mjo-common.tex
@@ -23,12 +23,21 @@
 % A pair of things.
 \providecommand*{\pair}[2]{ \left({#1},{#2}\right) }
 
+% A triple of things.
+\providecommand*{\triple}[3]{ \left({#1},{#2},{#3}\right) }
+
 % The Cartesian product of two things.
 \providecommand*{\cartprod}[2]{ {#1}\times{#2} }
 
 % The Cartesian product of three things.
 \providecommand*{\cartprodthree}[3]{ \cartprod{{#1}}{\cartprod{{#2}}{{#3}}} }
 
+% The direct sum of two things.
+\providecommand*{\directsum}[2]{ {#1}\oplus{#2} }
+
+% The factorial operator.
+\providecommand*{\factorial}[1]{ {#1}! }
+
 %
 % Product spaces
 %