Merge pull request #2 from Salanoid/main

Thank you! Looks good!

2 files changed, 66 insertions, 0 deletions

diff --git a/languages/r/ruby/README.md b/languages/r/ruby/README.md
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+Download Ruby version 3 or above
+
+Run by lambda-core.rb like this: `ruby lambda-core.rb`
\ No newline at end of file
diff --git a/languages/r/ruby/lambda-core.rb b/languages/r/ruby/lambda-core.rb
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+# LOGIC
+_true = ->(x) { ->(y) { x } }
+_false = ->(x) { ->(y) { y } }
+_not = ->(b) { b[_false][_true] }
+_and = ->(b1) { ->(b2) { b1[b2][_false] } }
+_or = ->(b1) { ->(b2) { b1[_true][b2] } }
+
+# CHURCH NUMERALS
+_zero = ->(f) { ->(x) { x } }
+_succ = ->(n) { ->(f) { ->(x) { f[n[f][x]] } } }
+_pred = ->(n) {
+  ->(f) {
+    ->(x) {
+      n[->(g) { ->(h) { h[g[f]] } }][->(u) { x }][->(a) { a }]
+    }
+  }
+}
+_one = _succ[_zero]
+
+# HELPERS - not pure lambda calculus
+def read_bool(b)
+  puts b["t"]["f"]
+end
+
+def read_church(n)
+  puts n[->(x) { x + 1 }][0]
+end
+
+# EXAMPLES
+puts "LOGIC"
+puts "---------------"
+puts "TRUE/FALSE"
+read_bool(_true) # t
+read_bool(_false) # f
+
+puts "NOT"
+read_bool(_not[_true]) # f
+read_bool(_not[_false]) # t
+
+puts "AND"
+read_bool(_and[_true][_true]) # t
+read_bool(_and[_true][_false]) # f
+read_bool(_and[_false][_true]) # f
+read_bool(_and[_false][_false]) # f
+
+puts "OR"
+read_bool(_or[_true][_true]) # t
+read_bool(_or[_true][_false]) # t
+read_bool(_or[_false][_true]) # t
+read_bool(_or[_false][_false]) # f
+
+puts "\nCHURCH NUMERALS"
+puts "---------------"
+puts "ZERO/SUCC"
+read_church(_zero) # 0
+read_church(_one) # 1
+read_church(_succ[_one]) # 2
+read_church(_succ[_succ[_one]]) # 3
+
+puts "PRED"
+read_church(_pred[_one]) # 0
+read_church(_pred[_succ[_one]]) # 1
+read_church(_pred[_succ[_succ[_one]]]) # 2