Fix test

Author: shashi

test/polyform.jl

@@ -80,7 +80,7 @@ end
 
 @testset "as_polynomial" begin
 
-    @syms x y
+    @syms x y z
     @eqtest as_polynomial((f, x, y) -> f(gcd(x, y)), 10x+10y, 5*(x^2-y^2)) == 5x + 5y
     @test as_polynomial((f, x, y) -> f(gcd(x, y)), 10x+10y, 5*(x^2-y^2), polyform=true) isa PolyForm
     @test repr(as_polynomial((f, x, y) -> f(gcd(x, y)), 10x+10y, 5*(x^2-y^2), polyform=true)) == repr(5x + 5y)