Referential transparency

3 minutes, 23 seconds

The Order of Evaluation - slide 2 : 26

Two equal expressions can substitute each other without affecting the meaning of a functional program

Referential transparency
- provides for easy equational reasoning about a program
- does not rely on a particular notion of equality
  - Reference equality, shallow equality and deep equality cannot be distinguished by functional means
- is a major contrast to imperative programming

Equals can be replaced by equals