Add permissive-licensed Coq samples

BSD-2-Clause: https://github.com/jscert/jscert

  * JSCorrectness.v
  * JSInterpreterExtraction.v
  * JSNumber.v
  * JSPrettyInterm.v

MIT/Expat: https://github.com/clarus/coq-atm

  * Computation.v
  * Main.v
  * Spec.v

samples/Coq/Main.v

@@ -0,0 +1,42 @@
+Require Import FunctionNinjas.All.
+Require Import ListString.All.
+Require Import Computation.
+
+Import C.Notations.
+
+Definition error (message : LString.t) : C.t :=
+  do_call! Command.ShowError message in
+  ret.
+
+Definition main : C.t :=
+  call! card_is_valid := Command.AskCard in
+  if card_is_valid then
+    call! pin := Command.AskPIN in
+    match pin with
+    | None => error @@ LString.s "No PIN given."
+    | Some pin =>
+      call! pin_is_valid := Command.CheckPIN pin in
+      if pin_is_valid then
+        call! ask_amount := Command.AskAmount in
+        match ask_amount with
+        | None => error @@ LString.s "No amount given."
+        | Some amount =>
+          call! amount_is_valid := Command.CheckAmount amount in
+          if amount_is_valid then
+            call! card_is_given := Command.GiveCard in
+            if card_is_given then
+              call! amount_is_given := Command.GiveAmount amount in
+              if amount_is_given then
+                ret
+              else
+                error @@ LString.s "Cannot give you the amount. Please contact your bank."
+            else
+              error @@ LString.s "Cannot give you back the card. Please contact your bank."
+          else
+            error @@ LString.s "Invalid amount."
+        end
+      else
+        error @@ LString.s "Invalid PIN."
+    end
+  else
+    error @@ LString.s "Invalid card.".