A regular function that is only defined between lower and higher.
If two functions intersect their higher and lower bounds respectively.
The second will take precedence where f(lower).
A lower partial function is a function that is defined by segments valid from [x..infinite[, or until it hits another function’s start.
It starts searching at -infinity and goes up to infinity, and takes the last seen function that contains the desired invariable value (x).
Define a functions defined by multiple functions parts.
See BoundedFunction.
Uses bounds as [lower,higher],
except in the case of a lower bound overlapping a higher bound.
In this case, the lower bound always take precedence.