mjo-common: add \Fn for generic fields.

[mjotex.git] / mjo-common.tex

diff --git a/mjo-common.tex b/mjo-common.tex
index 284d5a5fe9460a2ef4e32c7e5c5320784f0402fd..6b357abdbec9b5cdd53dd4c037d2d2e67375432b 100644 (file)
--- a/mjo-common.tex
+++ b/mjo-common.tex
@@ -39,6 +39,18 @@
 % A seven-tuple of things.
 \newcommand*{\septuple}[7]{ \left({#1},{#2},{#3},{#4},{#5},{#6},{#7}\right) }
 
+% The "least common multiple of" function. Takes a nonempty set of
+% things that can be multiplied and ordered as its argument. Name
+% chosen for synergy with \gcd, which *does* exist already.
+\newcommand*{\lcm}[1]{ \operatorname{lcm}\of{{#1}} }
+\ifdefined\newglossaryentry
+  \newglossaryentry{lcm}{
+    name={\ensuremath{\lcm{X}}},
+    description={the least common multiple of the elements of $X$},
+    sort=l
+  }
+\fi
+
 % The factorial operator.
 \newcommand*{\factorial}[1]{ {#1}! }
 
@@ -130,6 +142,19 @@
   }
 \fi
 
+% The n-dimensional product space of a generic field F.
+\newcommand*{\Fn}[1][n]{
+  \mathbb{F}\if\detokenize{#1}\detokenize{1}{}\else^{#1}\fi
+}
+
+\ifdefined\newglossaryentry
+  \newglossaryentry{F}{
+    name={\ensuremath{\Fn[1]}},
+    description={a generic field},
+    sort=F
+  }
+\fi
+
 
 % An indexed arbitrary binary operation such as the union or
 % intersection of an infinite number of sets. The first argument is