X-Git-Url: http://gitweb.michael.orlitzky.com/?p=mjotex.git;a=blobdiff_plain;f=mjo-linear_algebra.tex;fp=mjo-linear_algebra.tex;h=5fce75a403b83ace1b686c622f05ea24e1248363;hp=ebf4acddc359c7b02b6c9f81f29b05564a6290d8;hb=7a60af0c2fa38f05aecd84b530d3c5b87eaf3de7;hpb=7709fae36c4df0568e70a534c06caf8f566e033b

diff --git a/mjo-linear_algebra.tex b/mjo-linear_algebra.tex
index ebf4acd..5fce75a 100644
--- a/mjo-linear_algebra.tex
+++ b/mjo-linear_algebra.tex
@@ -71,3 +71,19 @@
     \fi
   }
 }
+
+
+%
+% Orthogonal direct sum.
+%
+% Wasysym contains the \ocircle that we use in \directsumperp.
+\usepackage{wasysym}
+\usepackage{scalerel}
+\DeclareMathOperator{\oplusperp}{\mathbin{
+  \ooalign{
+    $\ocircle$\cr
+    \raisebox{\noexpand{0.65\height}}{${\vstretch{0.5}{\perp}}$}\cr
+  }
+}}
+
+\newcommand*{\directsumperp}[2]{ {#1}\oplusperp{#2} }