diff --git a/basic-geometry/cotes-number.c b/basic-geometry/cotes-number.c
index fc7cc57..f00206b 100644
--- a/basic-geometry/cotes-number.c
+++ b/basic-geometry/cotes-number.c
@@ -34,6 +34,9 @@ extern inline void bgc_cotes_number_get_exponation_fp64(const BgcCotesNumberFP64
 extern inline void bgc_cotes_number_combine_fp32(const BgcCotesNumberFP32* number1, const BgcCotesNumberFP32* number2, BgcCotesNumberFP32* result);
 extern inline void bgc_cotes_number_combine_fp64(const BgcCotesNumberFP64* number1, const BgcCotesNumberFP64* number2, BgcCotesNumberFP64* result);
 
+extern inline void bgc_cotes_number_exclude_fp32(const BgcCotesNumberFP32* base, const BgcCotesNumberFP32* excludant, BgcCotesNumberFP32* difference);
+extern inline void bgc_cotes_number_exclude_fp64(const BgcCotesNumberFP64* base, const BgcCotesNumberFP64* excludant, BgcCotesNumberFP64* difference);
+
 extern inline void bgc_cotes_number_get_rotation_matrix_fp32(const BgcCotesNumberFP32* number, BgcMatrix2x2FP32* matrix);
 extern inline void bgc_cotes_number_get_rotation_matrix_fp64(const BgcCotesNumberFP64* number, BgcMatrix2x2FP64* matrix);
 
diff --git a/basic-geometry/cotes-number.h b/basic-geometry/cotes-number.h
index e4944a6..1990948 100644
--- a/basic-geometry/cotes-number.h
+++ b/basic-geometry/cotes-number.h
@@ -277,6 +277,26 @@ inline void bgc_cotes_number_combine_fp64(const BgcCotesNumberFP64* number1, con
     );
 }
 
+// ================= Exclusion ================== //
+
+inline void bgc_cotes_number_exclude_fp32(const BgcCotesNumberFP32* base, const BgcCotesNumberFP32* excludant, BgcCotesNumberFP32* difference)
+{
+    bgc_cotes_number_set_values_fp32(
+        base->cos * excludant->cos + base->sin * excludant->sin,
+        base->sin * excludant->cos - base->cos * excludant->sin,
+        difference
+    );
+}
+
+inline void bgc_cotes_number_exclude_fp64(const BgcCotesNumberFP64* base, const BgcCotesNumberFP64* excludant, BgcCotesNumberFP64* difference)
+{
+    bgc_cotes_number_set_values_fp64(
+        base->cos * excludant->cos + base->sin * excludant->sin,
+        base->sin * excludant->cos - base->cos * excludant->sin,
+        difference
+    );
+}
+
 // ============== Rotation Matrix =============== //
 
 inline void bgc_cotes_number_get_rotation_matrix_fp32(const BgcCotesNumberFP32* number, BgcMatrix2x2FP32* matrix)