diff --git a/Nasal/io.nas b/Nasal/io.nas
index 78a8e4678..dc0e0d8c0 100644
--- a/Nasal/io.nas
+++ b/Nasal/io.nas
@@ -28,6 +28,12 @@ var is_directory = func(path) {
     else return 0;
 };
 
+var is_regular_file = func(path) {
+    var tmp = stat(path);
+    if (tmp != nil and tmp[11] == "reg") return 1;
+    else return 0;
+};
+
 # <path> the path that should be searched for subdirectories
 # returns a vector of subdirectory names
 var subdirectories = func(path) {
diff --git a/Nasal/math.nas b/Nasal/math.nas
index 098c993cd..838856e14 100644
--- a/Nasal/math.nas
+++ b/Nasal/math.nas
@@ -43,3 +43,7 @@ var mod = func(n, m) {
 
 var _iln10 = 1/ln(10);
 var log10 = func(x) { ln(x) * _iln10 }
+
+var approx_eq = func (a,b, d = 0.000001) {
+    return (abs(a-b) < d);
+}
\ No newline at end of file