Bounded Linear Temporal Logic (LTL) operators.

# Documentation

always :: Int -> Spec Bool -> Spec BoolSource

Property `s`

holds for the next `n`

periods. If `n == 0`

, then `s`

holds
in the current period. We require `n >= 0`

.
E.g., if `p = always 2 s`

, then we have the following relationship between the streams generated:
```
s => T T T T F F F F ...
p => T T F F F F F F ...
```

eventually :: Int -> Spec Bool -> Spec BoolSource

Property `s`

holds at some period in the next `n`

periods. If `n == 0`

,
then `s`

holds in the current period. We require `n >= 0`

.
E.g., if `p = eventually 2 s`

, then we have the following relationship between the streams generated:
```
s => F F F F T F T F ...
p => F F T T T T T T ...
```