foo "hello" : String × String
[Meta.synthInstance] HasAdd String ==> HasAdd String
[Meta.synthInstance] 
  [Meta.synthInstance] main goal HasAdd String
  [Meta.synthInstance.newSubgoal] HasAdd String
  [Meta.synthInstance.globalInstances] HasAdd String #[]
  [Meta.synthInstance] remaining fuel 999
  [Meta.synthInstance] failed
[Meta.synthInstance] HasAdd Bool ==> HasAdd Bool
[Meta.synthInstance] 
  [Meta.synthInstance] main goal HasAdd Bool
  [Meta.synthInstance.newSubgoal] HasAdd Bool
  [Meta.synthInstance.globalInstances] HasAdd Bool #[]
  [Meta.synthInstance] remaining fuel 999
  [Meta.synthInstance] failed