What is a full expression in C?

Question

I study C language from \"C Primer Plus\" book by Stephen Prata and it came to the point :

\"A full expression is one that’s not a subexpression of a lar

Answer 1

Consider the statement below

a = b + c;

a = b + c is an expression which is not a subexpression of any larger expression. This is called full expression.
b + c is a subexpression of the larger expression a = b + c therefore it is not a full expression. b is also a subexpression for the full expression a = b + c and subexpression b + c.