Despite Chinese & Japanese don’t like ‘4’ for the same sound as \si (death), ‘4’ is the magic number for all ideal compositions:
1) All TCM 药方 has 4 compositions : 君臣佐使
eg. “银翘解毒片” (Chinese Panadol) ：
银花 （君药）有毒， 但可以杀flu virus,
(佐药 Assistant ) 甘草,..
(使药 Smoothening, sweetening ) 蜂蜜
2）烹饪 Cuisine :
佐：mix veggies, 腊肠，烧肉，…
使：香料 (葱花，胡椒粉，garlics,… ), 麻油/鱼露
使：Cello,… Double base
Eg. “4-Color” Problem : the only one Math impossible by mathematicians but proven only by computer.
5) Exemplary Nation Racial Harmony
Eg. Switzerland / Singapore : 4 races & official languages.
6) War against Evils:
Eg. WW2 Allied :
USA, UK, France, China, against evils Japan & German (+Italy).
7) Four seasons :
8) Healthy Meal:
Fill 1/4 plate with wholegrains.
• Fill 1/4 plate with good sources of protein.
• Fill 1/4 plate with fruit and 1/4 plate of vegetables.
That’s why the 19-year-old Math genius Galois (1832 AD) proved by his invention Abstract Algebra the “Group Theory” that Polynomial equations with radical solution (+ – */,nth root) ONLY possible up to maximum degree 4.
That explains why the “A5-Group” Icosahydron (二十面体) structured SARs-like viruses (eg. COVID-19) WILL NEVER have “radical” drug SOLUTION, only possble killed by our own Antibody pre-trained by Vaccines (eg. mRNA or Sinovac… ).
Also humans impossible to have more than 四代同堂。
The 5th Generation Computer “Prolog Machine” by Japan in 1980s failed miserably.
Anything more than 4G has only “particular case” solution with physical limit beyond which we have to shift paradigm / technology to restart on another track.
Eg 5G by Huawei facing so much difficulty by Western sabotage, only by jumping to new “Quantum Communication Technology” to overcome these physical & artificial human resistance, whether they like it or not by Western countries.