Failed assertion

[mikeshulman]

rule A type ;;
let foo = derive ({x : A} P type) ({x : A} f : P{x}) (a : A) -> f{a} ;;

yields

Rule A is postulated.
val foo :> derivation = Fatal error: exception File "src/nucleus/sanity.ml", line 55, characters 5-11: Assertion failed

Feel free to ignore and/or scold me again for trying to use unfinished software.

[anjapetkovic]

Oh, yes, I know about that one. It's a problem in printing actually, but this should be dealt with. Thank you for pointing it out :)