如图,在正六边形\(ABCDEF\)中,有下列四个命题\((\) \()\)
\(① \overrightarrow{AC}+ \overrightarrow{AF}=2 \overrightarrow{BC}\); \(② \overrightarrow{AD}=2 \overrightarrow{AB}+2 \overrightarrow{AF}\);\(③ \overrightarrow{AC}⋅ \overrightarrow{AD}= \overrightarrow{AD}⋅ \overrightarrow{AE}\) \(④( \overrightarrow{AD}⋅ \overrightarrow{AF})⋅ \overrightarrow{EF}= \overrightarrow{AD}⋅( \overrightarrow{AF}⋅ \overrightarrow{EF})\)
其中真命题的个数是\((\) \()\)