Assertions are written inside a class sequence or written separatly?

can somebody post assertion with a testbench

In reply to agoel:
Concurrent assertions can be implemented only in static constructs like modules or interfaces but not in classes.

In reply to chr_sue:

in our top module we can write the assertions right.

In reply to agoel:
They can be implemented there, but it is not the best place.
Best is to create a specfic assertion module which is connected to your design using the bind construct.

In reply to chr_sue:

can you please explain with any example?i am not getting what you are saying?

In reply to agoel:
Please find ore details here.