diff --git a/inc/math.h b/inc/math.h
index d0ed241..923bf7d 100644
--- a/inc/math.h
+++ b/inc/math.h
@@ -11,6 +11,12 @@
 #include <stdint.h>
 
 
+#define FLT_MAX		3.4028234664e+38
+#define FLT_MIN		1.1754943508e-38
+#define DBL_MAX 	1.7976931348623158e+308
+#define DBL_MIN 	2.2250738585072014e-308
+
+
 #define M_E				2.718281828459045235360287471352662498L //e
 #define M_LOG2E			1.442695040888963407359924681001892137L //log_2 e
 #define M_LOG10E		0.434294481903251827651128918916605082L //log_10 e
@@ -27,7 +33,7 @@
 
 
 #define INFINITY	(__builtin_inff())
-#define M_NAN		(__builtin_nanf("0"))
+#define NAN			nan("")
 
 
 
@@ -37,6 +43,29 @@
 #endif
 
 
+static inline int32_t isinf(float x)
+{
+	if (x > FLT_MAX)
+		return 1;
+	else if (x < FLT_MIN)
+		return -1;
+	else
+		return 0;
+}
+
+
+static inline bool isnan(float x)
+{
+	return x != x;
+}
+
+
+static inline float nan(const char* arg)
+{
+	return __builtin_nanf(arg);
+}
+
+
 static inline float round(float x)
 {
 #ifdef ARM_MATH_CM7