proof demorgan3 : ~(A | B) => ~A & ~B  
proof demorgan4 : ~(A & B) => ~A | ~B
proof imp1 : ((A => B) => C) => (A | C) & (B => C)
proof imp2 : ((A | C) & (B => C)) => ((A => B) => C)

annotated proof orcomm : (A | B) => B | A
term orcomm : (A | B) => B | A
annotated proof curry : ((A & B) => C) => (A => (B => C))
term curry : ((A & B) => C) => (A => (B => C))
term uncurry : (A => B => C) => ((A & B) => C)