In reply to Ashmika:
I split that to two properties as below. Untested though.
// Sig1 will be high for a few numbers of clock cycles.
// Number of clocks are unknown
// sig2 can only be high for one clock cycle while sig1 is high.
$rose (sig1) |-> sig1 until_with sig2;
$rose (sig2) |=> !sig2;
// sig2 toggles do not care if sig1 is not high.
Good luck
Srini