Force precision of float casts to be <0

PRECISION.md

@@ -285,11 +285,8 @@ If $\delta$ is computed to be $0$, we replace it by the Taylor approximation of
 
 FloatCast is the operator casting values into floats.
 
-The same precision is needed for the output as for the input.
-
-**Question:** what happens if we cast an `int` value in `float` using that rule? 
-The precision will remain above $0$ and the output value will be interpreted as `int` because of that, defeating the purpose of a `float` cast.
-It would maybe be better to reassign precisions greater than $0$ to $-1$ in order to force the `float` typing.
+If we cast an `int` value in `float` without modifying the precision, it will remain above $0$ and the output value will be interpreted as `int` because of that, defeating the purpose of a `float` cast.
+Having observed that, we reassign precisions greater than $0$ to $-1$ in order to force the `float` typing.
 
 ## FloatNum
 

interval/intervalFloatCast.cpp

@@ -28,12 +28,10 @@ namespace itv {
 
 interval interval_algebra::FloatCast(const interval& x)
 {
-    return x;
+    // return x;
 
-    // alternatively, to force the float typing
-    /*
-        return {x.lo(), x.hi(), std::min(x.lsb(), -1)};
-    */
+    // LSB with -1 value to force the float typing
+    return {x.lo(), x.hi(), std::min(x.lsb(), -1)};
 }
 
 void interval_algebra::testFloatCast()