<s>
In	O
programming	O
languages	O
,	O
scientific	O
calculators	O
and	O
similar	O
common	B-Algorithm
operator	I-Algorithm
notation	I-Algorithm
or	O
operator	O
grammar	O
is	O
a	O
way	O
to	O
define	O
and	O
analyse	O
mathematical	O
and	O
other	O
formal	O
expressions	O
.	O
</s>
<s>
In	O
Prolog	B-Language
for	O
example	O
,	O
the	O
infix	O
operator	O
is	O
non-associative	O
,	O
so	O
constructs	O
such	O
as	O
are	O
syntax	O
errors	O
.	O
</s>
