1 files changed, 22 insertions, 0 deletions
diff --git a/core/tests/sub.c b/core/tests/sub.c
new file mode 100644
index 0000000..41c4037
--- /dev/null
+++ b/core/tests/sub.c
@@ -0,0 +1,22 @@
+#include <tri.h>
+#include <string.h>
+
+int main(int argc, char *argv[])
+{
+	assert(argc == 2);
+	char *s = argv[1];
+	tri_t a = tri_parse_default(s, strlen(s));
+	tri_t one = tri_from(1);
+
+	int64_t ba = tri_to(a);
+
+	for (size_t i = 0; i < 1000000000; ++i)
+		a = tri_sub(a, one);
+
+	assert(ba - 1000000000 == tri_to(a));
+
+	char r[32];
+	size_t l = tri_fmt_default(r, 32, a);
+	r[l] = '\0';
+	printf("%s\n", r);
+}