@acer

Perfectly well! Thak you so mauch

additionally for a link on exact chapter in the programming guide

@Kitonum 

By the way, the syntax with third argument 'pp' gives an exact solution without any external features like *``. Pl, see below

restart;
2*a*b*m[1]+4*a*b*m[2];
content(%, [m[1], m[2]], 'pp')*pp

@Kitonum 

Ok.Thank a lot for info

@vv 

Thank you so much

Looks magnificently. *`` is a real trick