anchor.diff:    let private name = "SyntaxError" 
     let private updater (ctors:Constructors) ctor = {ctors with SyntaxError=ctor} 
     
  -  let setupConstructor (env:Environment) =
  +  let setupConstructor (env:Env) =
       let proto = env.Prototypes.SyntaxError
       Error.Utils.setupConstructor env name proto updater
   
  -  let setupPrototype (env:Environment) =
  +  let setupPrototype (env:Env) =
       let proto = env.Prototypes.SyntaxError
       let ctor =  env.Constructors.SyntaxError
       Error.Utils.setupPrototype name ctor proto
  
positive.code:       error :> CO
  
      let setupConstructor (env:Env) (name:string) (proto:CO) update =
        let ctor = new Func<FunctionObject, CommonObject, BoxedValue, CommonObject>(constructor' proto)
        let ctor = Utils.createHostFunction env ctor
        
        ctor.Prototype <- env.Prototypes.Function
  
negative.code:   let private name = "TypeError" 
    let private updater (ctors:Constructors) ctor = {ctors with TypeError=ctor} 
    
    let setupConstructor (env:Env) =
      let proto = env.Prototypes.TypeError
      Error.Utils.setupConstructor env name proto updater
  
    let setupPrototype (env:Env) =
      let proto = env.Prototypes.TypeError
      let ctor = env.Constructors.TypeError
      Error.Utils.setupPrototype name ctor proto