Goal statement verification

[JMozes16]

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
We want there to be a goal statement at the bottom of the screen. This can hold a statement. If the last statement from the above part is the same as this and all of the statements in the simplification processes are correct, then display that the goal was reached

Describe alternatives you've considered
Consider how you want to display that the goal was successfully reached

Additional context
Pretty important