[examples] Remove unnecessary use of bool.Bool library.

examples/acasxu/property_10.why

 theory ACASXU_P10
   use ieee_float.Float64
-  use bool.Bool
   use int.Int
   use interpretation.Vector
   use interpretation.NeuralNetwork

examples/acasxu/property_2.why

 theory ACASXU_P2
   use ieee_float.Float64
-  use bool.Bool
   use int.Int
   use interpretation.Vector
   use interpretation.NeuralNetwork

examples/acasxu/property_4.why

 theory ACASXU_P4
   use ieee_float.Float64
-  use bool.Bool
   use int.Int
   use interpretation.Vector
   use interpretation.NeuralNetwork

examples/acasxu/property_5.why

 theory ACASXU_P5
   use ieee_float.Float64
-  use bool.Bool
   use int.Int
   use interpretation.Vector
   use interpretation.NeuralNetwork

examples/acasxu/property_6.why

 theory ACASXU_P6
   use ieee_float.Float64
-  use bool.Bool
   use int.Int
   use interpretation.Vector
   use interpretation.NeuralNetwork

examples/acasxu/property_7.why

 theory ACASXU_P7
   use ieee_float.Float64
-  use bool.Bool
   use int.Int
   use interpretation.Vector
   use interpretation.NeuralNetwork

examples/acasxu/property_8.why

 theory ACASXU_P8
   use ieee_float.Float64
-  use bool.Bool
   use int.Int
   use interpretation.Vector
   use interpretation.NeuralNetwork

examples/acasxu/property_9.why

 theory ACASXU_P9
   use ieee_float.Float64
-  use bool.Bool
   use int.Int
   use interpretation.Vector
   use interpretation.NeuralNetwork