So i guess this is exactly the solution that author intended? Overwise i dont get whats the point of hint.

Looks like not all inputs are displayed in log for C#.

For example in "conflicts" tests i can see only:

input("fn x => 0") == <> was ok
Test Failed
input("f = 5") == <> and not <5> => wrong solution, aborted!

But with Console.WriteLine(input) i can see:

x = 0
fn f => 1
fn x => 0
input("fn x => 0") == <> was ok
f = 5
Test Failed
input("f = 5") == <> and not <5> => wrong solution, aborted!

Also in "variables" tests in log i can see input("y") == <> and not <25> => wrong solution, aborted!

But in previous "function" tests with Console.WriteLine(input) (not in default log) i can see

x = 23
y = 25
z = 0
...

So I thought there should be different scopes for different sections of the tests. If not, then the answer in "variables" tests should be y = 25

.