Simplify symbolic equations based in assumptions

[Nick11014]

I am trying to simplify a symbolic equation like ( x * y ) / ( x + y ) using the assume() function.

If y is much greater than x, then:
x + y = y;
( x * y ) / ( x + y ) = ( x * y ) / ( y ) = x

What i tried to do is something like

Code:


assume(y >> x ); // >> does not work. just for exemplification
simplify(( x * y ) / ( x + y )); // returns x

Is this possible ?