Garner
Lower-triangular Matrix A square matrix A whose elements aij=0 for i
Uper-triangular Matrix A square matrix A whose elements aij=0 for i>j is called upper triangular matrix.
Suffrage.
chitons
An audile is a person whose mental imagery consists of sounds.
U2
A subset of some set X is, by definition, any set whose elements are entirely contained in X. So the answer is yes. As an example, take your infinite set, and select 3 or 10 or any finite number of your favorite elements in this set. The set of your chosen elements is a finite subset of the infinite set.
Prokaryotic.
d block elements, transition metals, transition elements are synonyms.The definition of d block after the IUPAC recommendation is "an element whose atom has a partially filled d sub-shell, or which can give rise to cations with an incomplete dsub-shell".
A finite set or a countably infinite set.
Elements
Rhetorical definition