Adding the four with shaded columns...

The terms that go with each are:

First image INPUT CONDITIONS
Yes
Yes
No

First image OUTPUT ASSERTIONS
NOT
MAY

Second Image INPUT CONDITIONS
Yes
Yes
Yes-AND-No

Second image OUTPUT ASSERTIONS
MUST
MAY

Third Image INPUT CONDITIONS
Yes
Yes-AND-No
Yes

Third image OUTPUT ASSERTIONS
MAY
SHOULD

Fourth image INPUT CONDITIONS
Yes
Yes-OR-No
Yes

Fourth image OUTPUT ASSERTIONS
SHOULD
MUST

Adding the key for the symbols for the Input Conditions and Output Assertions.

You can re-do the fonts for the words to match the site.

... I will prepare a 'mock-up' to show the sizing and layout I have in mind for desktop and mobile interfaces.

(Again) Fixing some details in the 4 graphics of the logic gate for the home page.

I have updated the 'key table' of symbols with a corresponding font, and a tweak to change "YES AND NO" ; "YES OR NOT" to "Yes-AND-No"; "Yes-OR-No".

Adding mock-up graphics to illustrate intended general layout for the home page on a horizontal computer monitor and on a vertical mobile device.

Restoring LogicGate 4 image (accidentally removed) and updating the Key Table, and the homepage mock-ups for horizonal computer monitor and for vertical mobile screen.

This should be complete

Thanks