# Applying Inversed Rules

If I have

{x->2,y->3,z->19}


and make many calculations and finaly get

First/@FactorInteger[57]


{3, 19}

how can I apply the inversed rules to get

{y,z}

without using

/.{2->x,3->y,19->z}

• Why wouldn't {3, 19} /. Map[Reverse, {x -> 2, y -> 3, z -> 19}] work? – J. M. is away May 11 '17 at 0:48
• it worked!thanks – J42161217 May 11 '17 at 0:55
• @Jenny_mathy You can also write Reverse[rules, {2}] – Coolwater May 11 '17 at 4:20