[F&O] 7.5.4 fn:substring-before

F&O section 7.5.4 (definition of function fn:substring-before) states:

"If the value of $arg2 is the zero-length string, then the function returns
the zero-length string."

But later example is given:
"fn:substring-before("Baloney!","") returns "Baloney!". "

Then 7.5.5 fn:substring-after states:

"If the value of $arg2 is the zero-length string, then the function returns
the value of $arg1."

I think error in definition of fn:substring-before, behavior should be the
same as in fn:substring-after.
"If the value of $arg2 is the zero-length string, then the function returns
the value of $arg1."

If definition is correct and example mistaken, I think it is bad idea to
return zero-length string in such case.

Best regards,
Noe Michejda
7th Portal S.C.