The problem for me was the difference between a constant and a variable. "Costs a dollar more" is not saying that the bat cost $1 as a constant. This was a var

The problem for me was the difference between a constant and a variable. "Costs a dollar more" is not saying that the bat cost $1 as a constant. This was a variable, relative price compared to the ball. Failure to understand the mutability--or lack thereof--of the symbols in the system is a source of deep woe.