process do not require memorizing or manipulating Information - issue 238

Hi folks

For issue 238 <https://github.com/w3c/coga/issues/238>  asks us to include
stopping case like the user have to make a math operation to access a
service.

This is covered in 4.7.5 - Pattern: Do Not Rely on Users Memorizing
Information - to cover cuculations and add their example
However we should change the name of the pattern. Maybe
 "process do not require  memorizing or manipulating information"

Also maybe we should add their examples.

All the best

Lisa