Escaping Interpretation in Answer and @@@ Operator

For obvious reasons, you may not wish everything  in the answer box to be interpreted, and instead prefer that parts are expected literally.

• To escape interpretation, the _ may be used. In this case _a_ expects the literal input “a” and not the value of the variable a.
• Text must generally be escaped, to not confuse with variables that have been assigned. For example if there is a variable a in the question, assigned the value 2, if you the write in the answer box sam, the “a” will be interpreted. It is correct to write _sam_. 
• Writing sam in answer box should throw the error “variables s, m, not found”

@@@ operator

Rarely, you may wish to expect a line of text, with an interpreted value mixed in. Imagine we wish to expect the answer: 

Sam’s answer was 22!

Where the 22 is always the value of a. We could do it like this:

_Sam’s answer was_ a_!_

However we provide an alternative method: the @@@ symbol, which allows us to interpret within escaped sequences. This is only useful in some cases where there are many variables in a long expected sentence. Such cases occur mainly in word exercises (English). In this case we might write:

_Sam’s answer was @@@a@@@!_