Difficulties with solving the exercises in the K Framework Tutorial - kframework

Question

Tutorial 1 Lesson 8 ( mu-defined )
My attempt is to substitute the existing rule : "rule mu X . E => E[(mu X . E) / X]"
with the rule :
rule mu X:KVar . E:Exp
=> let X =
(lambda $x . (( lambda X . E) (lambda $y . ($x $x $y))))
(lambda $x . (( lambda X . E) (lambda $y . ($x $x $y)))) [macro]"
Unfortanetely it wont compile. What am i doing wrong ? Is this solution correct ?
Tutorial 1 Lesson 8 ( SK-combinators )
They have this part in the README of the exercise:
" For example, lambda x . if x then y else z cannot be transformed into combinators as is,
but it can if we assume a builtin conditional function constant, say cond,
and desugar if_then_else_ to it. Then this expression becomes
lambda x . (((cond x) y) z), which we know how to transform. "
My struggle is with ' say cond, and desugar if_then_else_ to it. '
How do i do this part ? Any help would be appreciated.
Tutorial 2 Lesson 4 (purely-syntactic)
They have this part in the README of the exercise:
'Hint: make sequential composition strict(1) or seqstrict, and have
statements reduce to {} instead of .; and don't forget to make
{} a KResult (you may need a new syntactic category for that, which
only includes {} and is included in KResult).'
My struggle is with the part: ' and have
statements reduce to {} instead of .; and don't forget to make
{} a KResult (you may need a new syntactic category for that, which
only includes {} and is included in KResult)'
How do i do this ? Any hints ?
Tutorial 2 Lesson 4 (uninitialized-variables)
I have created the following module:
module UNDEFINED
rule <k> int (X,Xs => Xs);_ </k> <state> Rho:Map (.Map => X|->"##") </state>
requires notBool (X in keys(Rho))
endmodule
But this initializes variables with "##". How do i initialize a variable with "undefined" ? Any hints ?
Tutorial 3 Lesson 1 (callCC)
For this exercise i created a very similar code similar to the callcc:
syntax Exp ::= "callCC" Exp [strict]
syntax Val ::= cc(K)
rule <k> (callCC V:Val => V cc(K)) ~> _ </k>
rule <k> cc(K) V ~> _ => V ~> _ </k>
For some reason it wont compile . What am i doing wrong ? Is this solution correct ?