HTLC Stack.md

Stack	Description
OP_TRUE 0xfeedface 0x0363e177...5e09c943	Start
0xfeedface 0x0363e177...5e09c943	OP_IF pops OP_TRUE off the stack. This is used to determine whether we're redeeming the HTLC or attempting to recover funds after a timeout.
0x3684d458...14877709 0x0363e177...5e09c943	OP_SHA256 pops the preimage off the stack and places its SHA256 hash onto the top of the stack.
0x0363e177...5e09c943	OP_EQUALVERIFY pops the hash off the stack and compares it to the digest inside the transaction. OP_EQUALVERIFY allows transaction execution to continue since the digests are equal.
0x0363e177...5e09c943 0x0363e177...5e09c943	OP_DUP duplicates the top item on the stack, which in this case is the seller's public key.
0xfa88b8dd...7be47a33 0xfa88b8dd...7be47a33 0x0363e177...5e09c943	OP_HASH160 hashes the top stack item and places the hash onto the top of the stack. <seller pubkey hash> is also placed onto the top of the stack.
0x0363e177...5e09c943	OP_EQUALVERIFY (after OP_ENDIF) verifies the equality of the public key hashes. This is done to make sure that only the correct party can execute each branch of the OP_IF statement.
OP_TRUE	OP_CHECKSIG verifies that the transaction signature matches the provided public key.