The problem Cairo SBTn solves

The problem came to mind when thinking about how we could increase the value from the current NFT collections, what a NFT owner could do without depending on the entire collection appreciate in value?
That is what SBT can solve, it can bring identity and indivudal value for NFT items, being able to attach other NFTs to them.
It could have a lot of use cases, like in gaming, or even in more serious fields, like housing, having a tokenized home and attaching SBTns to it with indivudal information about the home.
In the metaverse, people probably will play as a character entering in form of NFT, not as a simple EOA, in that scenario NFT items also need to be treated as a personality, deserving a Soul Bound Token as well. It could even increase the value of the NFT.

Challenges we ran into

We have some problems when compiling the smart contract code.