From 1d94756e1a430c9ff36c642ff73ef6bdec149bbd Mon Sep 17 00:00:00 2001
From: Dmitry Vagner <dmitry.vagner@gmail.com>
Date: Sat, 25 Feb 2023 18:07:10 -0800
Subject: [PATCH] add inverse doc

---
 .../cpu/kernel/asm/curve/bn254/field_arithmetic/inverse.asm  | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/evm/src/cpu/kernel/asm/curve/bn254/field_arithmetic/inverse.asm b/evm/src/cpu/kernel/asm/curve/bn254/field_arithmetic/inverse.asm
index 8e821f82..6214f385 100644
--- a/evm/src/cpu/kernel/asm/curve/bn254/field_arithmetic/inverse.asm
+++ b/evm/src/cpu/kernel/asm/curve/bn254/field_arithmetic/inverse.asm
@@ -6,7 +6,10 @@
     MULFP254
 %endmacro
 
-// Non-deterministically provide the inverse modulo N.
+// Non-deterministically provide the inverse x^-1 of x modulo N.
+// If x === 0 mod N, this function panics.
+// Although the official prover provides the unique inverse <N
+// this macro only checks that x * x^-1 === 0 mod N
 %macro inv_fp254
     // stack:        x
     PROVER_INPUT(ff::bn254_base::inverse)