doc/output.tex: Fix synopsis for `sequence-output' macro.

diff --git a/doc/output.tex b/doc/output.tex
index 27826ff..456554c 100644 (file)
--- a/doc/output.tex
+++ b/doc/output.tex
@@ -167,7 +167,7 @@ until the third.  So the final processing order is
 
 \begin{describe}{mac}
     {sequence-output (@<stream-var> @<sequencer>)               \\ \ind
-      @{ :constraint (@<item-name>^*) @}                        \\
+      @[ :constraint (@<item-name>^*) @]                        \\
       @{ (@<item-name> @<form>^*) @}^*}
 \end{describe}