diff --git a/libraries/Interval/Interval.cpp b/libraries/Interval/Interval.cpp
index 8629434b..b1b0e814 100644
--- a/libraries/Interval/Interval.cpp
+++ b/libraries/Interval/Interval.cpp
@@ -2,16 +2,18 @@
 //    FILE: Interval.cpp
 //  AUTHOR: Rob Tillaart
 //    DATE: 2020-07-21
-// VERSION: 0.1.0
+// VERSION: 0.1.1
 // PURPOSE: Arduino library for Interval datatype
 //     URL: https://github.com/RobTillaart/Interval
 //
 //  0.0.1   2020-07-20  initial version (not complete)
 //  0.1.0   2020-12-30  arduino-ci, unit tests, setRange()
+//  0.1.1   2021-05-27  arduino-lint
 
 
 #include "Interval.h"
 
+
 Interval::Interval(float lo, float hi)
 {
   if (lo <= hi)
@@ -26,24 +28,28 @@ Interval::Interval(float lo, float hi)
   }
 };
 
+
 Interval::Interval(float f)
 {
   _lo = f;
   _hi = f;
 };
 
+
 Interval::Interval()
 {
   _lo = 0;
   _hi = 0;
 };
 
+
 float Interval::relAccuracy()
 {
   if (value() == 0.0) return -1;
   return abs(range() / value());  // TODO /2 ?
 }
 
+
 void Interval::setRange(float r)
 {
   float f = value();
@@ -74,21 +80,25 @@ Interval Interval::operator + (const Interval &in)
   return Interval(_lo + in._lo, _hi + in._hi);
 }
 
+
 Interval Interval::operator - (const Interval &in)
 {
   return Interval(_lo - in._hi, _hi - in._lo);
 }
 
+
 Interval Interval::operator * (const Interval &in)
 {
   return Interval(_lo * in._lo, _hi * in._hi);
 }
 
+
 Interval Interval::operator / (const Interval &in)
 {
   return Interval(_lo / in._hi, _hi / in._lo);
 }
 
+
 Interval Interval::operator += (const Interval &in)
 {
   _lo += in._lo;
@@ -96,6 +106,7 @@ Interval Interval::operator += (const Interval &in)
   return *this;
 }
 
+
 Interval Interval::operator -= (const Interval &in)
 {
   _lo -= in._hi;
@@ -103,6 +114,7 @@ Interval Interval::operator -= (const Interval &in)
   return *this;
 }
 
+
 Interval Interval::operator *= (const Interval &in)
 {
   _lo *= in._lo;
@@ -110,6 +122,7 @@ Interval Interval::operator *= (const Interval &in)
   return *this;
 }
 
+
 Interval Interval::operator /= (const Interval &in)
 {
   _lo /= in._hi;
@@ -128,6 +141,7 @@ bool Interval::operator == (const Interval &in)
   return ((_lo == in._lo) && (_hi == in._hi));
 }
 
+
 bool Interval::operator != (const Interval &in)
 {
   return ((_lo != in._lo) || (_hi != in._hi));
@@ -155,9 +169,5 @@ bool Interval::operator != (const Interval &in)
 // }
 
 
-
-
-
-
 // -- END OF FILE --
 
diff --git a/libraries/Interval/Interval.h b/libraries/Interval/Interval.h
index b87ec47a..5f36cb9b 100644
--- a/libraries/Interval/Interval.h
+++ b/libraries/Interval/Interval.h
@@ -3,20 +3,22 @@
 //    FILE: Interval.h
 //  AUTHOR: Rob Tillaart
 //    DATE: 2020-07-21
-// VERSION: 0.1.0
+// VERSION: 0.1.1
 // PURPOSE: Arduino library for Interval datatype
 //     URL: https://github.com/RobTillaart/Interval
 //
 // HISTORY:
 // see Interval.cpp file
 
+
 #include "Arduino.h"
 
-#define INTERVAL_LIB_VERSION      "0.1.0"
+#define INTERVAL_LIB_VERSION      (F("0.1.1"))
+
  
 class Interval: public Printable
 {
-  public:
+public:
   // CONSTRUCTOR
   Interval();
   Interval(float lo, float hi);
@@ -59,9 +61,7 @@ class Interval: public Printable
   // Interval operator  ^  (const Interval&);  // 
   //   smaller 
 
-
-
-  private:
+private:
   float   _lo;
   float   _hi;
   uint8_t _decimals = 3;
diff --git a/libraries/Interval/README.md b/libraries/Interval/README.md
index 013e3c9e..5662a5cb 100644
--- a/libraries/Interval/README.md
+++ b/libraries/Interval/README.md
@@ -23,7 +23,6 @@ It was inspired by the frink language which has an interval datatype.
 Frink itself is not investigated, so semantics are not necessary similar.
 
 
-
 ## Interface
 
 The Interval class implements the public interface of Printable.
@@ -107,6 +106,7 @@ The Probably group will be more like fuzzy logic so a float between 0..100%.
 - **bool <  ** 
 - **bool <= ** 
 
+
 ### Set operators
 
 **To be investigated** include:
diff --git a/libraries/Interval/examples/interval_demo/interval_demo.ino b/libraries/Interval/examples/interval_demo/interval_demo.ino
index 65d1bbe0..efbf8bcd 100644
--- a/libraries/Interval/examples/interval_demo/interval_demo.ino
+++ b/libraries/Interval/examples/interval_demo/interval_demo.ino
@@ -6,11 +6,13 @@
 //    DATE: 2020-07-21
 //     URL: https://github.com/RobTillaart/Interval
 
+
 #include "Interval.h"
 
 Interval x(1, 2);
 Interval y(2, 3);
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -23,10 +25,12 @@ void setup()
   Serial.println("\nDone...");
 }
 
+
 void loop()
 {
 }
 
+
 void test_print()
 {
   Serial.println(__FUNCTION__);
diff --git a/libraries/Interval/library.json b/libraries/Interval/library.json
index 5602d19c..b4d84a6b 100644
--- a/libraries/Interval/library.json
+++ b/libraries/Interval/library.json
@@ -15,7 +15,8 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/Interval"
   },
-  "version":"0.1.0",
+  "version": "0.1.1",
+  "license": "MIT",
   "frameworks": "*",
   "platforms": "*"
 }
diff --git a/libraries/Interval/library.properties b/libraries/Interval/library.properties
index 86c09ee7..5c44f09b 100644
--- a/libraries/Interval/library.properties
+++ b/libraries/Interval/library.properties
@@ -1,10 +1,10 @@
 name=Interval
-version=0.1.0
+version=0.1.1
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino library for Interval datatype
 paragraph=
-category=data processing
+category=Data Processing
 url=https://github.com/RobTillaart/Interval.git
 architectures=*
 includes=Interval.h
diff --git a/libraries/Interval/test/unit_test_001.cpp b/libraries/Interval/test/unit_test_001.cpp
index bd7594c6..4c5b1454 100644
--- a/libraries/Interval/test/unit_test_001.cpp
+++ b/libraries/Interval/test/unit_test_001.cpp
@@ -41,6 +41,7 @@ unittest_setup()
 {
 }
 
+
 unittest_teardown()
 {
 }
@@ -150,7 +151,6 @@ unittest(test_math_basic_2)
 }
 
 
-
 unittest(test_comparisons)
 {
   fprintf(stderr, "VERSION: %s\n", INTERVAL_LIB_VERSION );
@@ -183,11 +183,10 @@ unittest(test_comparisons)
   // assertTrue(x >= x);
   // assertTrue(x >= a);
   // assertFalse(x >= y);
-
 }
 
 
-
 unittest_main()
 
+
 // --------