I can find various derivations of ∫ dθ = 0 which are satisfactory, but none of ∫dθ θ =1. Cheng and Li says it's just a normalization convention, of course that assumes that the integral is finite. Is this just a matter of definition, or is there a better reason that that? And would any of this relate to the exterior calculus, since I believe Grassmann algebra is an example of (or is) exterior albegra. Thanks very much !