Basic Church numerals from book. [2.6]
Derive Church numeral 1. [2.6]
Write Church 1 as a function. [2.6]
Derive Church 2. [2.6]
Write Church 2 as a function. [2.6]
Derive add-2. [2.6]
Derive generalized addition function. [2.6]
Simulate run of add-church. [2.6]
Merge branch 'ex2.6'
Interval functions from book. [2.7]
Define upper-bound and lower-bound. [2.7]
Merge branch 'ex2.7'
Remove ordering. [2.7][2.8]
Define sub-interval. [2.8]
Merge branch 'ex2.8'
Check for spanning zero. [2.10]
Merge branch 'ex2.10'