1 files changed, 19 insertions, 3 deletions
diff --git a/Doc/Zsh/params.yo b/Doc/Zsh/params.yo
index ecedc3862..a4dd1a2ca 100644
--- a/Doc/Zsh/params.yo
+++ b/Doc/Zsh/params.yo
@@ -1082,7 +1082,7 @@ Code specified by the tt(-c) option to the command line that invoked
 the shell.
 )
 item(tt(cmdsubst))(
-Command substitution using of the tt(`)var(...)tt(`),
+Command substitution using the tt(`)var(...)tt(`),
 tt($+LPAR())var(...)tt(RPAR()), tt(${{)var(name)tt(}) var(...)tt(}),
 tt(${|)var(...)tt(}), or tt(${ )var(...)tt( }) constructs.
 )
@@ -1115,13 +1115,19 @@ item(tt(globsort))(
 Code executed to order files by the tt(o) glob qualifier.
 )
 item(tt(insubst))(
-The tt(<LPAR())var(...)tt(RPAR()) form of process substitution.
+The tt(>LPAR())var(...)tt(RPAR()) form of process substitution.
 )
 item(tt(loadautofunc))(
 Code read directly from a file to define an autoloaded function.
 )
+item(tt(math))(
+Code executed in the tt($+LPAR()LPAR())var(...)tt(RPAR()RPAR()) or
+tt(LPAR()LPAR())var(...)tt(RPAR()RPAR()) constructs,
+by the tt(let) builtin, in an array subscript, or in
+another arithmetic context.
+)
 item(tt(outsubst))(
-The tt(>LPAR())var(...)tt(RPAR()) form of process substitution.
+The tt(<LPAR())var(...)tt(RPAR()) form of process substitution.
 )
 item(tt(sched))(
 Code executed by the tt(sched) builtin.
@@ -1175,6 +1181,9 @@ the argument passed to the option.  Otherwise it is not set.
 vindex(ZSH_EXEPATH)
 item(tt(ZSH_EXEPATH))(
 Full pathname of the executable file of the current zsh process.
+This value should be accurate on Linux, macOS, FreeBSD, DragonflyBSD,
+NetBSD, Solaris, Cygwin, and their derivatives.  On other systems, it is
+determined from tt(argv[0]), which is not always accurate.
 )
 vindex(ZSH_NAME)
 item(tt(ZSH_NAME))(
@@ -1256,6 +1265,12 @@ vindex(COLUMNS)
 item(tt(COLUMNS) <S>)(
 The number of columns for this terminal session.
 Used for printing select lists and for the line editor.
+If the shell is non-interactive and a legal value is imported from the
+environment, it is preserved.  Otherwise, the value is reset on start-up
+and in response to certain events such as the receipt of a tt(SIGWINCH)
+signal.  Explicitly setting it to an illegal value such as tt(0) also
+resets it.  (Unsetting the parameter does not have this effect; it
+simply `hides' the value that the shell is tracking internally.)
 )
 vindex(CORRECT_IGNORE)
 item(tt(CORRECT_IGNORE))(
@@ -1462,6 +1477,7 @@ vindex(LINES)
 item(tt(LINES) <S>)(
 The number of lines for this terminal session.
 Used for printing select lists and for the line editor.
+See tt(COLUMNS).
 )
 vindex(LISTMAX)
 item(tt(LISTMAX))(