IFV connectivity Check failure debug

Hi, 

I am new to IFV and need your assistance in debugging one of the assertion failure.

Scenario : 

assertion -add -interactive { (<path1>:top_scanb == 0) |-> ((<path2>:out_clk) === (<path3>:in_clk)) } -name test

When the above assertion is RUN, we get Trigger - Pass, Status - Fail (5).

FormalVerifier> debug :test  //opens up Waveform and we observe that top_scanb is 'x'.  

Q1: What is that the tool is checking by making top_scanb = 'x'?

Formal Verifier> assertion -show :test -verbose -list // shows that there are around 85 signals that are uninitialized.

Q2: How to debug this further?

Thanks,

Rajratna