That chart is overcomplicated.
There are 3 independent markers. A, B, and +.
Blood can have A or not, B or not, and + or not. When the body doesn’t have the marker, it will react to the marker.
So when you have notA, and get A blood, you will have a reaction.
notA blood works for everyone, A blood only for A people. A people can take any blood, notA people only notA blood.
Now do this independently for the 3 markers. AB+ people have all markers so can take any combination. notAnotBnot+ people make blood everyone can take, since there are no markers, but they can’t take any other blood with any markers.
Unfortunately we call not+ -, notAnotB O, notAB B, and AnotB A. So + we invert properly but for A and B we omit them and instead of emptystring when no marker is present we invent O, presumably for 0 markers. This obfuscates the pattern.
That chart is overcomplicated.
There are 3 independent markers. A, B, and +.
Blood can have A or not, B or not, and + or not. When the body doesn’t have the marker, it will react to the marker.
So when you have notA, and get A blood, you will have a reaction.
notA blood works for everyone, A blood only for A people. A people can take any blood, notA people only notA blood.
Now do this independently for the 3 markers. AB+ people have all markers so can take any combination. notAnotBnot+ people make blood everyone can take, since there are no markers, but they can’t take any other blood with any markers.
Unfortunately we call not+ -, notAnotB O, notAB B, and AnotB A. So + we invert properly but for A and B we omit them and instead of emptystring when no marker is present we invent O, presumably for 0 markers. This obfuscates the pattern.
This is not complicated? When we entered XOR or NAND or whatever gates I checked out. Give me the chart.
You’re preaching to the choir here.
The chart is for people that have never tried to sing.