pierceTheorem = [st|
  (P->Q)->P     :A/CI
     -P         :A/~E
        P       :A/CI
          Q     :A/~E
          P     :3 R
          -P    :2 R
        Q       :4-6 -E
     P->Q       :3-7 CI 
     P          :8 1 CE 
     -P         :2 R
  P             :2-10 -E 
((P->Q)->P)->P  :1-11 CI |]
pierceTheorem = [st|
  (P->Q)->P     :A/CI
     -P         :A/~E
        P       :A/CI
          Q     :A/~E
          P     :3 R
          -P    :2 R
        Q       :4-6 -E
     P->Q       :3-7 CI 
     P          :8 1 CE 
     -P         :2 R
  P             :2-10 -E 
((P->Q)->P)->P  :1-11 CI |]
pierceTheorem = [st|
  (P->Q)->P     :A/CI
     -P         :A/~E
        P       :A/CI
          Q     :A/~E
          P     :3 R
          -P    :2 R
        Q       :4-6 -E
     P->Q       :3-7 CI 
     P          :8 1 CE 
     -P         :2 R
  P             :2-10 -E 
((P->Q)->P)->P  :1-11 CI |]