SEARCH NIP NIP ROT OVER ULT 2DROP DROP FALSE TUCK EQUAL DUP >R 2SWAP DUP R@ ULT 2DROP 2DROP RDROP FALSE R@ - + R> EQUAL DUP >R SEARCH SWAP R@ + SWAP R> - RDROP 2DROP 0 0 3 PICK >R SEARCH DROP R> TUCK - RDROP 2DROP 0 0 3 PICK >R DUP >R SEARCH OVER R@ + SWAP R> - ROT R@ - R> SWAP TRUE 2R> 2DROP FALSE DUP >R 3 PICK >R SEARCH SWAP R@ OVER R> - 2SWAP R@ + SWAP R> - TRUE 2R> 2DROP FALSE 2 PICK OVER ULT 2DROP FALSE DUP >R 3 PICK R@ EQUAL RDROP FALSE SWAP R@ + SWAP R> - TRUE 2 PICK OVER ULT 2DROP FALSE DUP >R 2OVER R@ - + R@ EQUAL RDROP FALSE R> - TRUE MATCH-HEAD