Bi-directional LSTM (BiLSTM) Kågebäck and Salomonsson (2016) leveraged a bidirectional LSTM that learns a context vector for the target word in the input sequence and predicts the word sense with a multi-layer perceptron.
we can compute the context vector c t for tth word similarly to bi-directional encoder as follows, are forward and backward LSTMs repectively, and f c (x t ) = M c 1(x t ) is a function that maps a word to continous embedding space.