Merge pull request #15 from Aditya-Chowdhry/set_enhancement

Added ⊂ , ⊃ ,∈ ,∉ , ∅

lib/unicode_math/set.rb

@@ -11,9 +11,31 @@ def self.included(base)
         define_method('∪') do |set|
           self | set
         end
+
+        define_method('⊂') do |set|
+          ((set.∩ self) == self)  
+        end
+
+        define_method('⊃') do |set|
+          ((self.∩ set) == set)  
+        end
+
+        define_method('∈') do |set|
+          (self.∩ set) == self
+        end
+
+        define_method('∉') do |set|
+          !((self.∩ set) == self)
+        end
+
+        define_method('∅') do
+          self.empty?
+        end
+
       end
     end
   end
 end
 
 Array.send(:include, UnicodeMath::Set)
+

spec/unicode_math/set_spec.rb

@@ -6,6 +6,8 @@
   before do
     @primes   = [2, 3, 5, 7]
     @odd_nums = [3, 5, 7, 9]
+    @superset = [1,2,3,4,5]
+    @subset   = [3,5]
   end
 
   it 'defines the intersection operator: ∩' do
@@ -17,4 +19,58 @@
     union = @primes.∪ @odd_nums
     expect(union).to eq([2, 3, 5, 7, 9])
   end
+
+  it 'defines subset A ⊂ B : true' do 
+    subset = @subset.⊂ @superset
+    expect(subset).to eq(true)
+  end
+
+  it 'defines subset A ⊂ B : false' do 
+    subset = @superset.⊂ @subset
+    expect(subset).to eq(false)
+  end
+
+  it 'defines superset A ⊃ B : false' do 
+    subset = @subset.⊃ @superset
+    expect(subset).to eq(false)
+  end
+
+  it 'defines superset A ⊃ B : true' do 
+    subset = @superset.⊃ @subset
+    expect(subset).to eq(true)
+  end
+
+  it 'defines A belongs to B, A ∈ B : false' do 
+    belongs_to = @superset.∈ @subset
+    expect(belongs_to).to eq(false)
+  end
+
+  it 'defines A belongs to B, A ∈ B : true' do 
+    belongs_to = @subset.∈ @superset
+    expect(belongs_to).to eq(true)
+  end
+
+  it 'defines A does not belong to B, A ∉ B : false' do 
+    not_belongs_to = @subset.∉ @superset
+    #Does @subset does not belong to @primes ?
+    #True if it doesn't belong 
+    expect(not_belongs_to).to eq(false)
+  end
+
+  it 'defines A does not belong to B, A ∉ B : true' do 
+    not_belongs_to = @superset.∉ @subset
+    expect(not_belongs_to).to eq(true)
+  end
+
+  it 'defines A is empty' do 
+    empty = @primes.∅
+    expect(empty).to eq(false)
+  end
+
+  it 'defines A is empty' do 
+    empty = [].∅
+    expect(empty).to eq(true)
+  end
+
 end
+