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README.md

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+# STAPPL: STAtically typed Probabilistic Programming Language
+
+STAPPL is a compiler for the STAtically typed Probabilistic Programming Language.
+
+## How to Use
+
+Install the necessary OCaml packages:
+```sh
+opam install . --deps-only
+```
+
+You can run the program using the following command:
+```sh
+dune exec -- stappl <program.stp>
+```
+
+This will parse and compile the program, perform inference, and save the distribution plot of the final query variable as a PNG image file.
+
+## Example
+Here's an example program and its components:
+
+### Input Program
+```ocaml
+# example.stp
+fun main() {
+  let z = sample(bernoulli(0.5)) in
+  let mu = (if (z = 0 - 0) then ~-.1.0 else 1.0) in
+  let d = normal(mu, 0.0 +. 1.0) in
+  let y = 0.5 in
+  observe(d, y);
+  z
+}
+```
+#### Pretty Print (-pp)
+```scheme
+((funs
+  (((name main) (params ())
+    (body
+     (Assign z (Sample (Call bernoulli ((Real 0.5))))
+      (Assign mu
+       (If (Eq (Var z) (Minus (Int 0) (Int 0))) (Rneg (Real 1)) (Real 1))
+       (Assign d (Call normal ((Var mu) (Radd (Real 0) (Real 1))))
+        (Assign y (Real 0.5) (Seq (Observe (Var d) (Var y)) (Var z))))))))))
+ (exp (Call main ())))
+```
+#### Graph Mode
+```scheme
+((vertices (X1 X2)) (arcs ((bernoulli X1) (X1 X2) (normal X2)))
+ (det_map
+  ((X1 (Dist_obj (dist bernoulli) (var X1) (args ((Real 0.5)))))
+   (X2
+    (If_pred Empty
+     (Dist_obj (dist normal) (var X2)
+      (args
+       ((If (Eq (Var X1) (Minus (Int 0) (Int 0))) (Rneg (Real 1)) (Real 1))
+        (Radd (Real 0) (Real 1)))))
+     One))))
+ (obs_map ((X2 (Real 0.5)))))
+```
+#### Inference Mode
+The output will be the distribution of `z` and its plot saved as `example.png`.
+
+## License
+STAPPL is available under the MIT license. See the [LICENSE](LICENSE) file for more info.