update comparison methods

Author: shashi

src/methods.jl

@@ -109,14 +109,14 @@ Base.real(s::Symbolic{<:Number}) = term(real, s)
 # binary ops that return Bool
 for (f, Domain) in [(==) => Number, (!=) => Number,
                     (<=) => Real,   (>=) => Real,
-                    (< ) => Real,   (> ) => Real,
+                    (isless) => Real,   (> ) => Real,
                     (& ) => Bool,   (| ) => Bool,
                     xor => Bool]
     @eval begin
         promote_symtype(::$(typeof(f)), ::Type{<:$Domain}, ::Type{<:$Domain}) = Bool
-        (::$(typeof(f)))(a::Symbolic{<:$Domain}, b::$Domain) = term($f, a, b, type=Bool)
-        (::$(typeof(f)))(a::Symbolic{<:$Domain}, b::Symbolic{<:$Domain}) = term($f, a, b, type=Bool)
-        (::$(typeof(f)))(a::$Domain, b::Symbolic{<:$Domain}) = term($f, a, b, type=Bool)
+        (::$(typeof(f)))(a::Symbolic, b::$Domain) = term($f, a, b, type=Bool)
+        (::$(typeof(f)))(a::Symbolic, b::Symbolic) = term($f, a, b, type=Bool)
+        (::$(typeof(f)))(a::$Domain, b::Symbolic) = term($f, a, b, type=Bool)
     end
 end