Implement less than checks in snark

[barryWhiteHat]

In circom <= and <= are not grater than and less than checks they do not create constraints.

Therefore https://github.com/barryWhiteHat/RollupNC/blob/master/tokens_transfer/tokens_transfer.circom#L88 checks are not enforced.

We would need to build a circuit to do the >= check which would work with binary decomposition.

[barryWhiteHat]

@GuthL can you check this is correct?

[vaibhavchellani]

Any updates on this ? How to enforce > or < constraints ?

[barryWhiteHat]

So there are two ideas to check a > b.

1. Use binary comparitor
2. We cant ask the operator to prime a number c such that a + c = b where c != 0 because their is an overflow So we have to ensure that a , b , c < 250 bits that way we cannot overlfow. because a_250_bits + b_250_bits can only be 251 bits in total.