Seems, that my C book was a little bit outdated or incorrect.
I found only such phrases like "...returns mostly one if true.", but not "...returns always one if true."

Also it seems, that most programmer trust not on it. Since I see always only:
if( expression == 0 )
if( expression != 0 )
if( expression )

but never:
if( expression == 1 )
if( expression != 1 )

And also it was the first time that I read such a code which do arithmetics with a logical expression:
x *= (a > b);


Thus I think, everybody can understand my doubts on the postings above.


Peter