/prog/ fibonacci code?

Since the first day I came to this BBS, I've been very curious for this fibonacci function on the side. I've been trying to make it work in different ways, but always fail to obtain a result. Have any of you gotten something interesting?

🐇 🏤 🍇
🐇🐖 🏁 ➡️ 🚂 🍇
👴 Let’s print a few fibonaccis.

🍮 i 0
🍮 a 0
🍮 b 1

🔁 ◀️ i 15 🍇
🍮 r ➕ a b
🍮 a b
🍮 b r
😀 🔷🔡🚂 r 10
🍫 i
🍉

🍎 0
🍉
🍉