Finished rat_to_R_inv, but had to weaken the statement of the lemma since (I believe) it's impossible to show that 0 = /0 in Coq std. reals.
Finished rat_to_R_inv, but had to weaken the statement of the lemma since (I believe) it's impossible to show that 0 = /0 in Coq std. reals.

gstew5/cage,gstew5/cage