--- a/doc/interpreter/expr.txi	Fri Dec 16 15:40:24 2022 -0500
+++ b/doc/interpreter/expr.txi	Fri Dec 16 15:59:46 2022 -0500
@@ -814,6 +814,11 @@
 preferring the longest possible match at any given point, it is more
 useful in this case.
 
+Note also that some combinations of binary operators and whitespace can
+create ambiguities with Octave's Command Syntax form of calling functions.
+See @ref{Command Syntax and Function Syntax} for more detail on avoiding
+such issues.
+
 @opindex @code{'}
 @DOCSTRING(ctranspose)
 

--- a/doc/interpreter/func.txi	Fri Dec 16 15:40:24 2022 -0500
+++ b/doc/interpreter/func.txi	Fri Dec 16 15:59:46 2022 -0500
@@ -1906,7 +1906,7 @@
 @section Command Syntax and Function Syntax
 @cindex commands functions
 
-Additionally to the function syntax described above (i.e., calling a function
+In addition to the function syntax described above (i.e., calling a function
 like @code{fun (arg1, arg2, @dots{})}), a function can be called using command
 syntax (for example, calling a function like @code{fun arg1 arg2 @dots{}}).  In
 that case, all arguments are passed to the function as strings.  For example,
@@ -1980,6 +1980,76 @@
 assigned to a variable, or multiple output arguments of a function should be
 returned, the function syntax must be used.
 
+It should be noted that mixing command syntax and binary operators can
+create ambiguities with mathematical and logical expressions that would use
+function syntax.  For example, all three of the statements
+
+@example
+arg1 - arg2
+arg1 -arg2
+arg1-arg2
+@end example
+
+@noindent
+could be interpreted as a subtraction operation between
+@code{arg1} and @code{arg2}.  The first two, however, could also be taken
+as a command syntax call to function @code{arg1}, in the first case with
+options @code{-} and @code{arg2}, and in the second case with option
+@code{-arg2}.
+
+Octave uses whitespace to interpret such expressions according to the
+following rules:
+
+@itemize @bullet
+@item
+Statements consisting of plain symbols without any operators that are
+separated only by whitespace are always treated as command syntax:
+
+@example
+arg1 arg2 arg3 ... argn
+@end example
+
+@item
+Statements without any whitespace are always treated as function syntax:
+@example
+arg1+arg2
+arg1&&arg2||arg3
+arg1+=arg2*arg3
+@end example
+
+@item
+If the first symbol is a constant (or special-valued named constant pi, i,
+I, j, J, e, NaN, or Inf) followed by a binary operator, the statement is
+treated as function syntax regardless of any whitespace or what follows the
+second symbol:
+@example
+7 -arg2
+pi+ arg2
+j * arg2 -arg3
+@end example
+
+@item
+If the first symbol is a function or variable and there is no whitespace
+separating the operator and the second symbol, the statement is treated
+as command syntax:
+@example
+arg1 -arg2
+arg1 &&arg2 ||arg3
+arg1 +=arg2*arg3
+@end example
+
+@item
+Any other whitespace combination will result in the statement being treated
+as function syntax.
+@end itemize
+
+Note 1:  If a special-valued named constant has been redefined as a
+variable, the interpreter will still process the statement with function
+syntax.
+
+Note 2:  Attempting to use a variable as @code{arg1} in a command being
+processed as command syntax will result in an error.
+
 
 @node Organization of Functions
 @section Organization of Functions Distributed with Octave