One Black Crow is a two candle bearish reversal candlestick pattern.

The first candle is a not short (but not necessarily long) white candle. The following does not check for the not short portion.

O1 < C1

The second candle is a not short (but necessarily long) black candle. The second candle opens below the close of the first candle and above the open of the first candle and closes below the open of the first candle.

C < O1 AND O1 < O AND O < C1

This candle forms in a uptrend. This is going to be defined here as three up closes in a row ending with the first candle.

C4 < C3 AND C3 < C2 AND C2 < C1

The resulting candlestick pattern is as follows.

C < O1 AND O1 < O AND O < C1 AND C4 < C3 AND C3 < C2 AND C2 < C1

Boolean PCFs for Candlestick Patterns