Added union(space,space)
BigFloat Cooley-Tukey FFT and Interval invariance

for H_0. Also, adding a small comment on the Σ operator, and renamed
the file.
Fix tablature
First go at adding piecewise
Fixed Jacobi conversion_rule
Fixed in for interval and evaluate for pw fun at vector
Restarted domainplot using Compose
Merge pull request #53 from MikaelSlevinsky/master

BigFloat Cooley-Tukey FFT and Interval invariance