Assertion doubt

In reply to santosh manur:

An assertion of the form

 
a |-> ##[1:$] b; 

Can never fail because if “b” is false, other threads of the consequent will be tested.

An assertion of the form

 
a |-> first_match(##[1:$] b) ##0 c; 

Will fail with the sequence b ##0 c occurs.

Rethink the assertion.
Ben