Boolean declaration in Scilla

gistfile1.txt

contract Boolean()

field a : Option Bool = None {Bool} (*declaring variable a with no value*)
field b : Bool = True (*declaring variable b with some fixed value*)

transition update_value()

    (*updating variable a*)
    c = False; (*declaring variable c in the transition*)
    tmp = Some {Bool} c;
    a := tmp; 
    
    (*updating variable b*)
    d= False;
    b:= d
      
end