TRUE.
```
$l = a
```
```
Starting on goal: $l = [a | true]
Goal arity 3: $l = [a | true]
nextSolution
  Push $l ("[]"(ice, cream))
  Resetting variable $l ("[]"(ice, cream))
  Push $a (_1)
  Push $b (_2)
  Resetting variable $b (_2)
  Resetting variable $a (_1)
  Push _1 ($l)
  Resetting variable _1 ($l)
  Push $x (_3)
  Push $y (_4)
  Resetting variable $y (_4)
  Resetting variable $x (_3)
  Push _3 ($l)
  Resetting variable _3 ($l)
  Push $x (_5)
  Push $y (_6)
  Resetting variable $y (_6)
  Resetting variable $x (_5)
  Push _5 ($l)
  Resetting variable _5 ($l)
  Push $list (_7)
  Push $x (_8)
  Push $cond (_9)
  Push $c (_10)
  Resetting variable $c (_10)
  Resetting variable $cond (_9)
  Resetting variable $x (_8)
  Resetting variable $list (_7)
  Push _7 ($l)
  Push _8 (a)
  Push _9 (true)
Got clause: _7 = [_8 | _9]
  Clause unifies to: $l = [a | true]
  gdash: _10 = new collector
Goal arity 4: _10 = new collector
   Push $x (_11)
   Resetting variable $x (_11)
   Push _11 (_10)
 Got clause: _11 = new collector
   Clause unifies to: _10 = new collector
  Clause is native.
   Push _10 (<collector>)
   gdash: [forall_impl ([a , true , <collector>])] or true
 Goal arity 3: [forall_impl ([a , true , <collector>])] or true
    Push $a (_12)
    Push $b (_13)
    Resetting variable $b (_13)
    Resetting variable $a (_12)
    Push _12 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Resetting variable _12 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Push $x (_14)
    Push $y (_15)
    Resetting variable $y (_15)
    Resetting variable $x (_14)
    Push _14 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Resetting variable _14 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Push $x (_16)
    Push $y (_17)
    Resetting variable $y (_17)
    Resetting variable $x (_16)
    Push _16 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Resetting variable _16 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Push $list (_18)
    Push $x (_19)
    Push $cond (_20)
    Push $c (_21)
    Resetting variable $c (_21)
    Resetting variable $cond (_20)
    Resetting variable $x (_19)
    Resetting variable $list (_18)
    Push _18 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Resetting variable _18 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Push $e (_22)
    Push $c (_23)
    Push $list (_24)
    Resetting variable $list (_24)
    Resetting variable $c (_23)
    Resetting variable $e (_22)
    Push _22 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Resetting variable _22 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Push $a (_25)
    Push $b (_26)
    Resetting variable $b (_26)
    Resetting variable $a (_25)
    Push _25 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Push _26 (true)
  Got clause: _25 or _26
    Clause unifies to: [forall_impl ([a , true , <collector>])] or true
    gdash: forall_impl ([a , true , <collector>])
  Goal arity 2: forall_impl ([a , true , <collector>])
     Push $x (_27)
     Push $collector (_28)
     Resetting variable $collector (_28)
     Resetting variable $x (_27)
     Push $x (_29)
     Resetting variable $x (_29)
     Push $x (_30)
     Resetting variable $x (_30)
     Push $x (_31)
     Resetting variable $x (_31)
     Push $x (_32)
     Resetting variable $x (_32)
     Push $x (_33)
     Push $cond (_34)
     Push $c (_35)
     Resetting variable $c (_35)
     Resetting variable $cond (_34)
     Resetting variable $x (_33)
     Push _33 (a)
     Push _34 (true)
     Push _35 (<collector>)
   Got clause: forall_impl ([_33 , _34 , _35])
     Clause unifies to: forall_impl ([a , true , <collector>])
     gdash: true
   Goal arity 0: true
    Got clause: true
      Clause unifies to: true
      gdash: saveTo ([a , <collector>])
    Goal arity 2: saveTo ([a , <collector>])
       Push $x (_36)
       Push $collector (_37)
       Resetting variable $collector (_37)
       Resetting variable $x (_36)
       Push _36 (a)
       Push _37 (<collector>)
     Got clause: saveTo ([_36 , _37])
       Clause unifies to: saveTo ([a , <collector>])
      Clause is native.
       gdash: false
     Goal arity 0: false
       Resetting variable _37 (<collector>)
       Resetting variable _36 (a)
       Push $x (_38)
       Resetting variable $x (_38)
       Push $x (_39)
       Resetting variable $x (_39)
       Push $x (_40)
       Resetting variable $x (_40)
       Push $x (_41)
       Resetting variable $x (_41)
       Push $x (_42)
       Push $cond (_43)
       Push $c (_44)
       Resetting variable $c (_44)
       Resetting variable $cond (_43)
       Resetting variable $x (_42)
       Push $c (_45)
       Push $a (_46)
       Push $b (_47)
       Resetting variable $b (_47)
       Resetting variable $a (_46)
       Resetting variable $c (_45)
       Push $x (_48)
       Resetting variable $x (_48)
       Push $x (_49)
       Resetting variable $x (_49)
     Resetting variable _35 (<collector>)
     Resetting variable _34 (true)
     Resetting variable _33 (a)
     Push $c (_50)
     Push $a (_51)
     Push $b (_52)
     Resetting variable $b (_52)
     Resetting variable $a (_51)
     Resetting variable $c (_50)
     Push $x (_53)
     Resetting variable $x (_53)
     Push $x (_54)
     Resetting variable $x (_54)
    Resetting variable _26 (true)
    Resetting variable _25 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Push $a (_55)
    Push $b (_56)
    Resetting variable $b (_56)
    Resetting variable $a (_55)
    Push _55 ("[]"(forall_impl, "()"("[]"(a, ",", true, ",", <collector>))))
    Push _56 (true)
  Got clause: _55 or _56
    Clause unifies to: [forall_impl ([a , true , <collector>])] or true
    gdash: true
  Goal arity 0: true
   Got clause: true
     Clause unifies to: true
     gdash: $l = retrieve (<collector>)
   Goal arity 4: $l = retrieve (<collector>)
      Push $x (_57)
      Resetting variable $x (_57)
      Push _57 ($l)
      Resetting variable _57 ($l)
      Push $x (_58)
      Push $retrieve (_59)
      Push $collector (_60)
      Resetting variable $collector (_60)
      Resetting variable $retrieve (_59)
      Resetting variable $x (_58)
      Push _58 ($l)
      Push _59 (retrieve)
      Push _60 (<collector>)
    Got clause: _58 = _59 (_60)
      Clause unifies to: $l = retrieve (<collector>)
     Clause is native.
      Push $l ("[]"(a))
      gdash: -
SUCCESS!
  solution found in step 55```
[done] 92 ms