Indexing :
yi			y(i), simple concatenation (might be confused with y*i)
y(i+1)	array type notation
Note the more clear & easy to read indexing used in this review for mixing indexes and t or other variables
...  example ai(t) -> a(i,t) 

Inequalities (second version for faster typing, symbolic processing)
≤		<=
≥		>=
≠		!=

Special notations 
~=	"not equal to", a Q'Nial programming language convention, which is often denoted in the literature as 
	<>		eg bash scripts
	!=		eg C programming
	etc
~= is NOT used in this work.

[super, sub]-script symbols 
"_cup" denotes variable values during ???   eg p4L23 Eq (9d)
"_ovr" denotes variable values during times s ∈ [t_til(0),0]???  eg ξ_ovr(t)
"_til" denotes variable values during ???   eg p4L38