There's been a Proof backlash of late. During the past year, critics started calling it "overrated" and "glib" -- though the long Broadway run of David Auburn's play continues to prove that Proof is highly appealing. The Unicorn's production put Cinnamon Schultz in the lead role of the depressed and brilliant daughter of a deceased mathematician, then let her be as difficult and unlikable as the script calls for. Richard Alan Nichols, Brian Paulette and Sarah Crawford helped Schultz make the mostly dark, sometimes funny play an invigorating experience.