diff --git a/smnp.dsp.md b/smnp.dsp.md
index 95c6125..9aa57a0 100644
--- a/smnp.dsp.md
+++ b/smnp.dsp.md
@@ -1,3 +1,44 @@
 # Functions
 ## `plot(...signals: list<int, float>)`
-## `plot(config: map<string><>, ...signals: map<string><>)`
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+Plots given lists as individual signals.
+
+## `plot(config: map<string><>, ...signals: map<string><>)`
+Plots given signals using global config map and individual maps with series.
+
+### Arguments
+* `config` - global config map, which includes following keys (all of them are optional):
+
+| KEY     | TYPE     | VALUE                                                                | DEFAULT |
+|:-------:|:--------:|:--------------------------------------------------------------------:|:-------:|
+| title   | `string` | The title of plot written at the very top of it.                     | -       |
+| output  | `string` | The output image file name. If passed, plot is not displayed.        | -       |
+| format  | `string` | The format of output image. Applicable only when `output` is passed. | png     | 
+
+Available formats:
+* png
+* jpg
+* bpm
+* gif
+* eps
+* pdf
+* svg
+
+* `signals` - a list of maps of following schema:
+
+| KEY     | TYPE   |VALUE                                                                | REQUIRED? | DEFAULT  |
+|:-------:|:------:|:-------------------------------------------------------------------:|:---------:|:--------:|
+| name    | `string` | The name of series (will be applied in legend).                   | Yes       | -        |
+| y | `list<int, float>` | The data to be plotted.                                       | Yes       | -        |
+| x | `list<int, float>` | The X series (horizontal axis).                               | No    | 0, 1, 2, ... |
+
+### Example
+```
+plot({ title -> "Example plot", output -> "myFile", format -> "pdf" },
+ { name -> "C", y -> wave([@C:32]) },
+ { name -> "D", y -> wave([@D:32]) },
+ { name -> "E", y -> wave([@E:32]) }
+);
+```
+
+## `fft(signal: list<int, float>)`
+Returns a signal passed through FFT/radix-2 algorithm as a list of floats.
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