6-A-1 (Triangle Assembly)
Triangle Assembly is the triangle that is formed between the arms and the shoulders. Homer assigns a number to each side of the triangle. The straight left arm is the forms Side One. The shoulders form Side Two. The right shoulder to the hands forms Side Three. Since the right arm can be bent or straightened...and remember, at impact the right arm should be slightly bent and after impact the right arm should straighten...the triangle can only change by changing the length of Side Three.
6-A-2 (Primary Lever Assembly)
Primary lever assembly is the left arm and the clubshaft and the 'lever' they form. Page 36 in the book goes over 3 different types of levers. Each lever has a fulcrum, a weight and a force.
In the primary lever assembly, the left shoulder is the fulcrum, the clubshaft down by the clubhead is the weight and the power (or 'force') is in between the weight (shaft) and the fulcrum (left shoulder). The pic on the bottom of page 67 shows Sally Kelley's primary lever assembly and where the fulcrum, weight and power (or force) are located.
The primary lever assembly is normally propelled by the Arms. The Arms are moved by the Power Accumulators and the Pressure Point #1 and/or Pressure Point #4 (we'll get into these later). The hitter normally uses PP #1, but can use PP #4. The swinger almost exclusively uses PP #4, but can use PP #1. There's more of a likelihood of a hitter using PP #4 than a swinger using PP #1.
6-A-2 (Secondary Lever Assembly)
Homer states that there's basically two lever assemblys. One is the left arm and the clubshaft. That is the Primary Lever Assembly.
The other Lever Assembly is just the club. That is the Secondary Lever Assembly. This Secondary Lever Assembly is also a Form III Lever.
In this Secondary Lever, the flat left wrist is the fulcrum, the clubhead is the weight and in between the the left wrist and clubhead is the power. Whereas the Primary Lever Assembly is propelled by the arms, the Accumulators and Pressure Points 1 and 4. The Secondary Lever is propelled by the hands, the Accumulators and Pressure Points 2 and 3.
Just briefly says that until after the follow thru, the left arm is never bent and the right arm is never straight.
The Left Arm bends if and when it is carried --- NOT THROWN --- closer than about 45 degrees to the Shoulder line.I would say that the 45 degrees to the shoulder line is right about where the left arm is in the pic below:
As far as 'carried' vs. 'thrown', I believe what Homer is saying is that the left arm is 'carried' if it is moved by the pivot and/or right arm thrust instead of the golfer actively 'throwing' the left arm in the follow thru.