I don't understand why Visual Studio Code underline Compute command in blue. The error message tell nothing about that.
Inductive day : Type :=
| monday
| tuesday
| wednesday
| thursday
| friday
| saturday
| sunday.
Definition next_weekday (d:day) : day :=
match d with
| monday => tuesday
| tuesday => wednesday
| wednesday => thursday
| thursday => friday
| friday => monday
| saturday => monday
| sunday => monday
end.
Compute (next_weekday friday).
Compute (next_weekday (next_weekday saturday)).
Example test_next_weekday:
(next_weekday (next_weekday saturday)) = tuesday.
There is no error message. Errors are underlined in red, and warnings in orange.
Blue means that there is a message associated with the command, but it's not a bad message, just the output of the command.
If you put your pointer over the blue line, it will show the output of the Compute
command.