pexpr_cases2: fixes e :: "pexpr"   and ea :: "pexpr" obtains c :: "int" and ca :: "int" where "e = PExpr1 (PCnst c__)" and "ea = PExpr1 (PCnst ca)"   | c :: "int" and n :: "nat" where "e = PExpr1 (PCnst cb__)" and "ea = PExpr1 (PVar n__)"   | c :: "int" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr1 (PCnst cc__)" and "ea = PExpr1 (PAdd e1__ e2__)"   | c :: "int" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr1 (PCnst cd__)" and "ea = PExpr1 (PSub e1a__ e2a__)"   | c :: "int" and e' :: "pexpr" where "e = PExpr1 (PCnst ce__)" and "ea = PExpr1 (PNeg e'__)"   | c :: "int" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr1 (PCnst cf__)" and "ea = PExpr2 (PMul e1b__ e2b__)"   | c :: "int" and e' :: "pexpr" and n :: "nat" where "e = PExpr1 (PCnst cg__)" and "ea = PExpr2 (PPow e'a__ na__)"   | n :: "nat" and c :: "int" where "e = PExpr1 (PVar nb__)" and "ea = PExpr1 (PCnst ch__)"   | n :: "nat" and na :: "nat" where "e = PExpr1 (PVar nc__)" and "ea = PExpr1 (PVar naa__)"   | n :: "nat" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr1 (PVar nd__)" and "ea = PExpr1 (PAdd e1c__ e2c__)"   | n :: "nat" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr1 (PVar ne__)" and "ea = PExpr1 (PSub e1d__ e2d__)"   | n :: "nat" and e' :: "pexpr" where "e = PExpr1 (PVar nf__)" and "ea = PExpr1 (PNeg e'b__)"   | n :: "nat" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr1 (PVar ng__)" and "ea = PExpr2 (PMul e1e__ e2e__)"   | n :: "nat" and e' :: "pexpr" and na :: "nat" where "e = PExpr1 (PVar nh__)" and "ea = PExpr2 (PPow e'c__ nab__)"   | e1 :: "pexpr" and e2 :: "pexpr" and c :: "int" where "e = PExpr1 (PAdd e1f__ e2f__)" and "ea = PExpr1 (PCnst ci__)"   | e1 :: "pexpr" and e2 :: "pexpr" and n :: "nat" where "e = PExpr1 (PAdd e1g__ e2g__)" and "ea = PExpr1 (PVar ni__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e1a :: "pexpr" and e2a :: "pexpr" where "e = PExpr1 (PAdd e1h__ e2h__)" and "ea = PExpr1 (PAdd e1aa__ e2aa__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e1a :: "pexpr" and e2a :: "pexpr" where "e = PExpr1 (PAdd e1i__ e2i__)" and "ea = PExpr1 (PSub e1ab__ e2ab__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e' :: "pexpr" where "e = PExpr1 (PAdd e1j__ e2j__)" and "ea = PExpr1 (PNeg e'd__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e1a :: "pexpr" and e2a :: "pexpr" where "e = PExpr1 (PAdd e1k__ e2k__)" and "ea = PExpr2 (PMul e1ac__ e2ac__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e' :: "pexpr" and n :: "nat" where "e = PExpr1 (PAdd e1l__ e2l__)" and "ea = PExpr2 (PPow e'e__ nj__)"   | e1 :: "pexpr" and e2 :: "pexpr" and c :: "int" where "e = PExpr1 (PSub e1m__ e2m__)" and "ea = PExpr1 (PCnst cj__)"   | e1 :: "pexpr" and e2 :: "pexpr" and n :: "nat" where "e = PExpr1 (PSub e1n__ e2n__)" and "ea = PExpr1 (PVar nk__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e1a :: "pexpr" and e2a :: "pexpr" where "e = PExpr1 (PSub e1o__ e2o__)" and "ea = PExpr1 (PAdd e1ad__ e2ad__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e1a :: "pexpr" and e2a :: "pexpr" where "e = PExpr1 (PSub e1p__ e2p__)" and "ea = PExpr1 (PSub e1ae__ e2ae__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e' :: "pexpr" where "e = PExpr1 (PSub e1q__ e2q__)" and "ea = PExpr1 (PNeg e'f__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e1a :: "pexpr" and e2a :: "pexpr" where "e = PExpr1 (PSub e1r__ e2r__)" and "ea = PExpr2 (PMul e1af__ e2af__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e' :: "pexpr" and n :: "nat" where "e = PExpr1 (PSub e1s__ e2s__)" and "ea = PExpr2 (PPow e'g__ nl__)"   | e' :: "pexpr" and c :: "int" where "e = PExpr1 (PNeg e'h__)" and "ea = PExpr1 (PCnst ck__)"   | e' :: "pexpr" and n :: "nat" where "e = PExpr1 (PNeg e'i__)" and "ea = PExpr1 (PVar nm__)"   | e' :: "pexpr" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr1 (PNeg e'j__)" and "ea = PExpr1 (PAdd e1t__ e2t__)"   | e' :: "pexpr" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr1 (PNeg e'k__)" and "ea = PExpr1 (PSub e1u__ e2u__)"   | e' :: "pexpr" and e'a :: "pexpr" where "e = PExpr1 (PNeg e'l__)" and "ea = PExpr1 (PNeg e'aa__)"   | e' :: "pexpr" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr1 (PNeg e'm__)" and "ea = PExpr2 (PMul e1v__ e2v__)"   | e' :: "pexpr" and e'a :: "pexpr" and n :: "nat" where "e = PExpr1 (PNeg e'n__)" and "ea = PExpr2 (PPow e'ab__ nn__)"   | e1 :: "pexpr" and e2 :: "pexpr" and c :: "int" where "e = PExpr2 (PMul e1w__ e2w__)" and "ea = PExpr1 (PCnst cl__)"   | e1 :: "pexpr" and e2 :: "pexpr" and n :: "nat" where "e = PExpr2 (PMul e1x__ e2x__)" and "ea = PExpr1 (PVar no__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e1a :: "pexpr" and e2a :: "pexpr" where "e = PExpr2 (PMul e1y__ e2y__)" and "ea = PExpr1 (PAdd e1ag__ e2ag__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e1a :: "pexpr" and e2a :: "pexpr" where "e = PExpr2 (PMul e1z__ e2z__)" and "ea = PExpr1 (PSub e1ah__ e2ah__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e' :: "pexpr" where "e = PExpr2 (PMul e1ai__ e2ai__)" and "ea = PExpr1 (PNeg e'o__)"   | e1 :: "pexpr" and e2 :: "pexpr" and e1a :: "pexpr" and e2a :: "pexpr" where "e = PExpr2 (PMul e1aj__ e2aj__)" and "ea = PExpr2 (PMul e1a e2a)"   | e1 :: "pexpr" and e2 :: "pexpr" and e' :: "pexpr" and n :: "nat" where "e = PExpr2 (PMul e1al__ e2al__)" and "ea = PExpr2 (PPow e'p__ np__)"   | e' :: "pexpr" and n :: "nat" and c :: "int" where "e = PExpr2 (PPow e'q__ nq__)" and "ea = PExpr1 (PCnst c)"   | e' :: "pexpr" and n :: "nat" and na :: "nat" where "e = PExpr2 (PPow e'r__ nr__)" and "ea = PExpr1 (PVar nac__)"   | e' :: "pexpr" and n :: "nat" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr2 (PPow e's__ ns__)" and "ea = PExpr1 (PAdd e1am__ e2am__)"   | e' :: "pexpr" and n :: "nat" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr2 (PPow e't__ nt__)" and "ea = PExpr1 (PSub e1an__ e2an__)"   | e' :: "pexpr" and n :: "nat" and e'a :: "pexpr" where "e = PExpr2 (PPow e'u__ nu__)" and "ea = PExpr1 (PNeg e'ac__)"   | e' :: "pexpr" and n :: "nat" and e1 :: "pexpr" and e2 :: "pexpr" where "e = PExpr2 (PPow e'v__ nv__)" and "ea = PExpr2 (PMul e1 e2)"   | e' :: "pexpr" and n :: "nat" and e'a :: "pexpr" and na :: "nat" where "e = PExpr2 (PPow e' n)" and "ea = PExpr2 (PPow e'a na)"