diff --git a/math.c b/math.c
index 5400737..afaa570 100644
--- a/math.c
+++ b/math.c
@@ -105,7 +105,7 @@ math_atan2(VALUE obj, VALUE y, VALUE x)
  *
  *  Domain: (-INFINITY, INFINITY)
  *
- *  Codomain: [-1, 1]
+ *  Codomain: [-1.0, 1.0]
  *
  *    Math.cos(Math::PI) #=> -1.0
  *
@@ -127,7 +127,7 @@ math_cos(VALUE obj, VALUE x)
  *
  *  Domain: (-INFINITY, INFINITY)
  *
- *  Codomain: [-1, 1]
+ *  Codomain: [-1.0, 1.0]
  *
  *    Math.sin(Math::PI/2) #=> 1.0
  *
@@ -168,7 +168,7 @@ math_tan(VALUE obj, VALUE x)
  *
  *  Computes the arc cosine of +x+. Returns 0..PI.
  *
- *  Domain: [-1, 1]
+ *  Domain: [-1.0, 1.0]
  *
  *  Codomain: [0, PI]
  *
@@ -195,7 +195,7 @@ math_acos(VALUE obj, VALUE x)
  *
  *  Computes the arc sine of +x+. Returns -PI/2..PI/2.
  *
- *  Domain: [-1, -1]
+ *  Domain: [-1.0, -1.0]
  *
  *  Codomain: [-PI/2, PI/2]
  *
@@ -251,7 +251,7 @@ cosh(double x)
  *
  *  Domain: (-INFINITY, INFINITY)
  *
- *  Codomain: [1, INFINITY)
+ *  Codomain: [1.0, INFINITY)
  *
  *    Math.cosh(0) #=> 1.0
  *
@@ -309,7 +309,7 @@ tanh(double x)
  *
  *  Domain: (-INFINITY, INFINITY)
  *
- *  Codomain: (-1, 1)
+ *  Codomain: (-1.0, 1.0)
  *
  *    Math.tanh(0) #=> 0.0
  *
@@ -328,9 +328,9 @@ math_tanh(VALUE obj, VALUE x)
  *
  *  Computes the inverse hyperbolic cosine of +x+.
  *
- *  Domain: [1, INFINITY)
+ *  Domain: [1.0, INFINITY)
  *
- *  Codomain: [0, INFINITY)
+ *  Codomain: [0.0, INFINITY)
  *
  *    Math.acosh(1) #=> 0.0
  *
@@ -376,7 +376,7 @@ math_asinh(VALUE obj, VALUE x)
  *
  *  Computes the inverse hyperbolic tangent of +x+.
  *
- *  Domain: (-1, 1)
+ *  Domain: (-1.0, 1.0)
  *
  *  Codomain: (-INFINITY, INFINITY)
  *
@@ -408,7 +408,7 @@ math_atanh(VALUE obj, VALUE x)
  *
  *  Domain: (-INFINITY, INFINITY)
  *
- *  Codomain: (0, INFINITY)
+ *  Codomain: (0.0, INFINITY)
  *
  *    Math.exp(0)       #=> 1.0
  *    Math.exp(1)       #=> 2.718281828459045
@@ -443,7 +443,7 @@ static double math_log1(VALUE x);
  *  If additional second argument is given, it will be the base
  *  of logarithm. Otherwise it is +e+ (for the natural logarithm).
  *
- *  Domain: (0, INFINITY)
+ *  Domain: (0.0, INFINITY)
  *
  *  Codomain: (-INFINITY, INFINITY)
  *
@@ -514,7 +514,7 @@ extern double log2(double);
  *
  *  Returns the base 2 logarithm of +x+.
  *
- *  Domain: (0, INFINITY)
+ *  Domain: (0.0, INFINITY)
  *
  *  Codomain: (-INFINITY, INFINITY)
  *
@@ -557,7 +557,7 @@ math_log2(VALUE obj, VALUE x)
  *
  *  Returns the base 10 logarithm of +x+.
  *
- *  Domain: (0, INFINITY)
+ *  Domain: (0.0, INFINITY)
  *
  *  Codomain: (-INFINITY, INFINITY)
  *
@@ -600,9 +600,9 @@ math_log10(VALUE obj, VALUE x)
  *
  *  Returns the non-negative square root of +x+.
  *
- *  Domain: [0, INFINITY)
+ *  Domain: [0.0, INFINITY)
  *
- *  Codomain:[0, INFINITY)
+ *  Codomain:[0.0, INFINITY)
  *
  *    0.upto(10) {|x|
  *      p [x, Math.sqrt(x), Math.sqrt(x)**2]
@@ -640,9 +640,9 @@ math_sqrt(VALUE obj, VALUE x)
  *
  *  Returns the cube root of +x+.
  *
- *  Domain: [0, INFINITY)
+ *  Domain: [0.0, INFINITY)
  *
- *  Codomain:[0, INFINITY)
+ *  Codomain:[0.0, INFINITY)
  *
  *    -9.upto(9) {|x|
  *      p [x, Math.cbrt(x), Math.cbrt(x)**3]
@@ -741,7 +741,7 @@ math_hypot(VALUE obj, VALUE x, VALUE y)
  *
  *  Domain: (-INFINITY, INFINITY)
  *
- *  Codomain: (-1, 1)
+ *  Codomain: (-1.0, 1.0)
  *
  *    Math.erf(0) #=> 0.0
  *
@@ -762,7 +762,7 @@ math_erf(VALUE obj, VALUE x)
  *
  *  Domain: (-INFINITY, INFINITY)
  *
- *  Codomain: (0, 2)
+ *  Codomain: (0.0, 2.0)
  *
  *    Math.erfc(0) #=> 1.0
  *
@@ -783,7 +783,7 @@ math_erfc(VALUE obj, VALUE x)
  *
  *  Domain: (-INFINITY, INFINITY)
  *
- *  Codomain: (0, 1)
+ *  Codomain: (0.0, 1.0)
  *
  *    Math.normcdf(0) #=> 0.5
  *