git-issue-4939a.dfy(99,19): Warning: This ensures clause is part of a bodyless function. Add the {:axiom} attribute to it or the enclosing function to suppress this warning
git-issue-4939a.dfy(142,11): Warning: because of cyclic dependencies among constructor argument types, no instances of datatype 'T' can be constructed
git-issue-4939a.dfy(144,11): Warning: because of cyclic dependencies among constructor argument types, no instances of datatype 'Mutual' can be constructed
git-issue-4939a.dfy(145,11): Warning: because of cyclic dependencies among constructor argument types, no instances of datatype 'Nutual' can be constructed
git-issue-4939a.dfy(25,32): Error: cannot prove termination; try supplying a decreases clause
git-issue-4939a.dfy(68,12): Error: cannot prove termination; try supplying a decreases clause
git-issue-4939a.dfy(68,12): Error: decreases expression must be bounded below by 0
git-issue-4939a.dfy(67,23): Related location: this proposition could not be proved
git-issue-4939a.dfy(105,27): Error: cannot prove termination; try supplying a decreases clause
git-issue-4939a.dfy(105,27): Error: decreases expression must be bounded below by 0
git-issue-4939a.dfy(104,23): Related location: this proposition could not be proved

Dafny program verifier finished with 12 verified, 5 errors
