Dear Subhra,

as discussed bilaterally and after clarification of your question the
situation is as follows:

Let us assume A and B have a channel in which A has 4 tokens and B has 6

Now A offers an HTLC with the amount of 2 tokens and B accepts (receives)
the offer then A and B both have negotiated the HTLC output in the most
recent commitment transaction.

If A stops responding and B has to force close the channel a commitment
transaction with 3 UTXOs will hit the chain. One UTXO with 2 tokens
spendable by A, another one with 6 tokens spendable by B and the received
HTLC output with 2 tokens. This one can be spend by two different
conditions as in the offchain protocol

1.) Before the timelock of the HTLC has passed B can spend the output if B
knows his to_local HTLC secret AND the preimage. OR
2.) after the timelock A can spend the output if A knows the to_remote HTLC

the mechanism with HTLCs can be read upon in BOLT 2 (channel operation
and the scripts can be seen in BOLT 3:

A less technical summary that is more focused on explaining the concepts is
currently being developed in the routing chapter of mastering the lightning

With kind regards Rene Pickhardt

On Tue, May 5, 2020 at 8:06 PM Subhra Mazumdar <> wrote:

> Hi,
>      I am having a doubt regarding force closure of channel. Suppose A->B
> there is an htlc which has been established for transfering fund. Now
> suppose for some unfortunate reason B doesnt have the witness to resolve
> htlc and the mean time A suffers crash fault. Then can B close the channel
> given that it has no way out of resolving the htlc due to lack of witness?
> _______________________________________________
> Lightning-dev mailing list


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