def tokens_probability(tokens, language)
      tokens.inject(0.0) do |sum, token|
        sum += Math.log(token_probability(token, language))
      end
    end
def tokens_probability(tokens, language)
      tokens.inject(0.0) do |sum, token|
        sum += Math.log(token_probability(token, language))
      end
    end
Internal: Probably of set of tokens in a language occurring - P(D | C)

 tokens   - Array of String tokens.
 language - Language to check.

 Returns Float between 0.0 and 1.0.