Update tests

Author: YingboMa

test/order.jl

@@ -5,15 +5,15 @@ SymbolicUtils.show_simplified[] = false
 
 @syms a b c
 
-function istotal(x,y)
+function istotal(x, y)
     #either
     if x <ₑ y
         return !(y <ₑ x)
     elseif y <ₑ x
         return !(x <ₑ y) # already tested
     else
         # neither, equal
-        return true
+        return isequal(x, y)
     end
 end
 
@@ -81,8 +81,7 @@ end
 @testset "small terms" begin
     # this failing was a cause of a nasty stackoverflow #82
     @syms a
-    @test Term(^, [a, -1]) <ₑ (a + 2)
-    @test !((a + 2) <ₑ Term(^, [a, -1]))
+    istotal(Term(^, [a, -1]), (a + 2))
 end
 
 @testset "transitivity" begin