IVy is a research tool intended to allow interactive development of protocols and their proofs of correctness and to provide a platform for developing and experimenting with automated proof techniques. In particular, IVy provides interactive visualization of automated proofs, and supports a use model in which the human protocol designer and the automated tool interact to expose errors and prove correctness.
The code in https://github.com/kenmcmil/ivy/blob/master/test/tc1.ivy seems not to work.
Ivy generates the errors: