In Section 13.2 replace the last paragraph with the following two paragraphs. The actual change is to modify the first sentence as shown in blue. Change the second sentence to be the start of a new paragraph and then add the items in blue.

Unless otherwise specified, the default input skew is 1step and the default output skew is 0.

A step is a special time unit defined to be the smallest possible delay throughout the simulation, that is, the smallest global precision. Like all other time units, a step is not a keyword. A 1step input skew allows input signals to sample their steady-state values immediately before the clock event (i.e., at read-only-synchronize immediately before time advanced to the clock event). Unlike other time units, which represent physical units, a step cannot be used to set or modify the either the precision or the timeunit.