move seed to right before tests, add a literal function example to docs

Author: shashi

README.md

@@ -25,12 +25,15 @@ If you are a Julia package develper in need of a rule rewriting system for your
 ```julia
 julia> using SymbolicUtils
 
-julia> @syms x::Real y::Real z::Complex
+julia> @syms x::Real y::Real z::Complex f(::Number)::Real
 (x, y, z)
 
 julia> 2x^2 - y + x^2
 (3 * (x ^ 2)) + (-1 * y)
 
+julia> f(sin(x)^2 + cos(x)^2) + z
+f(1) + z
+
 julia> r = @rule sinh(im * ~x) => sin(~x)
 sinh(im * ~x) => sin(~x)
 

test/fuzz.jl

@@ -100,10 +100,10 @@ function fuzz_test(ntrials)
 end
 
 using Random: seed!
-seed!(6174)
 
 @testset "Fuzz test" begin
 
+    seed!(6174)
     for i=1:2000
         fuzz_test(10)
     end

test/rulesets.jl

@@ -1,7 +1,5 @@
 using Random: shuffle, seed!
 
-seed!(1729)
-
 @testset "Numeric" begin
     @syms a::Integer b c d x::Real y::Number
     @test simplify(x - y) == x + -1*y
@@ -71,6 +69,8 @@ end
 @testset "Shuffle Rules" begin
     @syms a::Integer b c d x::Real y::Number
     R1 = RuleSet(SymbolicUtils.SIMPLIFY_RULES)
+
+    seed!(1729)
     R2 = RuleSet(shuffle(R1.rules))
     simplify_shuffle_tester(ex) = (R2 ∘ R1)(ex) == (R1 ∘ R2)(ex)