Bug #1777168: replace operator names "opa"... with "op1"... and mark everything up as literal,

to enhance readability.

Doc/reference/expressions.rst

@@ -1008,12 +1008,12 @@ Comparisons can be chained arbitrarily, e.g., ``x < y <= z`` is equivalent to
 ``x < y and y <= z``, except that ``y`` is evaluated only once (but in both
 cases ``z`` is not evaluated at all when ``x < y`` is found to be false).
 
-Formally, if *a*, *b*, *c*, ..., *y*, *z* are expressions and *opa*, *opb*, ...,
-*opy* are comparison operators, then *a opa b opb c* ...*y opy z* is equivalent
-to *a opa b* :keyword:`and` *b opb c* :keyword:`and` ... *y opy z*, except that
-each expression is evaluated at most once.
+Formally, if *a*, *b*, *c*, ..., *y*, *z* are expressions and *op1*, *op2*, ...,
+*opN* are comparison operators, then ``a op1 b op2 c ... y opN z`` is equivalent
+to ``a op1 b and b op2 c and ... y opN z``, except that each expression is
+evaluated at most once.
 
-Note that *a opa b opb c* doesn't imply any kind of comparison between *a* and
+Note that ``a op1 b op2 c`` doesn't imply any kind of comparison between *a* and
 *c*, so that, e.g., ``x < y > z`` is perfectly legal (though perhaps not
 pretty).