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diff --git a/.gitignore b/.gitignore
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+*.beam
diff --git a/README.md b/README.md
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+
+* https://www.erlang.org/downloads#prebuilt
diff --git a/erlang_ls.config b/erlang_ls.config
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+++ b/erlang_ls.config
diff --git a/hello.erl b/hello.erl
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+++ b/hello.erl
diff --git a/step-01/README.md b/step-01/README.md
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+Test your environment:
+
+```bash
+$ erl
+Erlang/OTP 25 [erts-13.2.2.5] [source] [64-bit] [smp:12:12] [ds:12:12:10] [async-threads:1] [jit:ns]
+
+Eshell V13.2.2.5  (abort with ^G)
+1> halt().
+$
+```
diff --git a/step-02/README:md b/step-02/README:md
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+Basic syntax demonstration!
+
+```erlang
+-module(step02).
+-export([double/1]).
+
+double(X) ->
+     2 * X.
+```
+
+* Statements are terminated with a full stop: ".".
+* `module` declares the name of the module. Should match file name by default.
+* `export` names functions to export out of this module. Will be usable by other modules. The `func/N` syntax means *the function `func`* with *N* arguments.
+* `double(X)` is a function declaration and implementation.
+
+Using this module looks like this:
+
+```
+1> c(step02).
+{ok,step02}
+2> step02:double(4).
+8
+```
+
+* The `c/1` function compiles a module. Notice that it returns ok and a module name.
+* To call the function, the module is explicitly named.
diff --git a/step-02/step02.erl b/step-02/step02.erl
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+-module(step02).
+-export([double/1]).
+
+double(X) ->
+     2*X.
diff --git a/step-03/README.md b/step-03/README.md
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+# More syntax
+
+A function is identified by its name (`foo`) and the number of arguments it has. A function can be declared multiple times while pattern matching on it's arguments:
+
+```
+fac(1) ->
+    1;
+fac(N) ->
+    N * fac(N - 1).
+```
+
+Notice the semi-colon between the declarations.
+
+Try out [tut1](./tut1.erl):
+
+```
+1> c(tut1).
+{ok,tut1}
+2> tut1:fac(1).
+1
+3> tut1:fac(10).
+3628800
+```
+
+# Atoms
+
+An atom is data type that starts with a lower-case letter. In the previous examples `ok` and `tut1` are atoms. They are kinda like unmodifyable strings, but are used as identifiers.
+
+[tut2](./tut2.erl) is another example of overloading, but with atoms:
+
+```
+1> c(tut2).
+{ok,tut2}
+2> tut2:convert(23, centimeter).
+58.42
+```
+
+# More pattern matching
+
+Tuples are dentonated as: `{a, b, c}`. They can be used when pattern matching as seen in [tut3](./tut3.erl).
+
+```
+1> c(tut3).
+{ok,tut3}
+2> tut3:convert_length({inch, 23}).
+{centimeter,58.42}
+```
+
+# Lists
+
+Lists are dentonated as: `[a, b, c]`, for example:
+
+```erlang
+Temps = [
+    {moscow, {c, -10}},
+    {cape_town, {f, 70}},
+    {stockholm, {c, -4}},
+    {paris, {f, 28}},
+    {london, {f, 36}}
+].
+```
+
+Lists are, as they commonly are in functional languages, linked lists and it is common to work on the head of the list:
+
+```
+1> [First | Rest] = Temps.
+[{moscow,{c,-10}},
+ {cape_town,{f,70}},
+ {stockholm,{c,-4}},
+ {paris,{f,28}},
+ {london,{f,36}}]
+2> First.
+{moscow,{c,-10}}
+3> Rest.
+[{cape_town,{f,70}},
+ {stockholm,{c,-4}},
+ {paris,{f,28}},
+ {london,{f,36}}]
+```
+
+```
+1> [First, Second | Rest] = Temps.
+[{moscow,{c,-10}},
+ {cape_town,{f,70}},
+ {stockholm,{c,-4}},
+ {paris,{f,28}},
+ {london,{f,36}}]
+2> First.
+{moscow,{c,-10}}
+3> Second.
+{cape_town,{f,70}}
+4> Rest.
+[{stockholm,{c,-4}},{paris,{f,28}},{london,{f,36}}]
+```
+
+# Maps
+
+Maps are dentonated as `#{foo => bar}`
diff --git a/step-03/tut1.erl b/step-03/tut1.erl
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+-module(tut1).
+-export([fac/1]).
+
+fac(1) ->
+    1;
+fac(N) ->
+    N * fac(N - 1).
diff --git a/step-03/tut2.erl b/step-03/tut2.erl
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+-module(tut2).
+-export([convert/2]).
+
+convert(M, inch) ->
+    M / 2.54;
+
+convert(N, centimeter) ->
+    N * 2.54.
diff --git a/step-03/tut3.erl b/step-03/tut3.erl
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+-module(tut3).
+-export([convert_length/1]).
+
+convert_length({centimeter, X}) ->
+    {inch, X / 2.54};
+convert_length({inch, Y}) ->
+    {centimeter, Y * 2.54}.
diff --git a/step-04/README.md b/step-04/README.md
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+++ b/step-04/README.md
diff --git a/step-04/tut17.erl b/step-04/tut17.erl
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+-module(tut17).
+
+-export([start_ping/1, start_pong/0,  ping/2, pong/0]).
+
+ping(0, Pong_Node) ->
+    {pong, Pong_Node} ! finished,
+    io:format("ping finished~n", []);
+
+ping(N, Pong_Node) ->
+    {pong, Pong_Node} ! {ping, self()},
+    receive
+        pong ->
+            io:format("Ping received pong~n", [])
+    end,
+    ping(N - 1, Pong_Node).
+
+pong() ->
+    receive
+        finished ->
+            io:format("Pong finished~n", []);
+        {ping, Ping_PID} ->
+            io:format("Pong received ping~n", []),
+            Ping_PID ! pong,
+            pong()
+    end.
+
+start_pong() ->
+    register(pong, spawn(tut17, pong, [])).
+
+start_ping(Pong_Node) ->
+    spawn(tut17, ping, [3, Pong_Node]).