Relationships lost when mirror is not copy

Hi all,

I don't do it often but if I've started a sketch, then decide I want the lines and arcs mirrored, but not copied about a line, all the relationships and definitions are usually lost.

I then go through the sketch adding back in all the horizontal, vertical, tangential, equal, dimensions, etc...

I have used the Tools - Dimensions - Fully Define Sketch button with some success.

Depending on the complexity of the sketch this all can take some time.

Does anyone know if there is a setting I ought to change somewhere, or is this how it is?

Adrian.

SolidworksSketching