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doc-src/Tutorial/Recdef/ack
author paulson
Tue, 19 Jan 1999 11:16:07 +0100
changeset 6139 26abad27b03c
parent 6100 40d66bc3e83f
child 9255 2ceb11a2e190
permissions -rw-r--r--
simplified thanks to the arithmetic prover

consts ack :: "nat*nat => nat"
recdef ack "measure(%m. m) ** measure(%n. n)"
  "ack(0,n)         = Suc n"
  "ack(Suc m,0)     = ack(m, 1)"
  "ack(Suc m,Suc n) = ack(m,ack(Suc m,n))"
isabelle