Which one of the following statements not correct for convolution?

 Properties of convolution of two signals:

→ Convolution of an odd and even function is an odd function.

→ Convolution of two odd functions is an even function.

→ Convolution of two even function is an even function

→ Convolution of two causal functions is causal function.

→ Convolution of two Anti causal function is Anticausal function.

→ Convolution of two unequal length rectangular pulse is trapezium.

→ Convolution of two equal length rectangular pulses is triangle.

→ Convolution of signal with periodic train of impulses is periodic representation of signal.

Therefore option (4) statement is not correct.