thinking

hypothesizing

proof by contradiction or indirect proof

reductio ad absurdum

mistake

non sequitur

starting place

handle

with corresponding changes

mutatis mutandis

counterexample

pathological exception

consequently

ipso facto

swallowing results

digesting proofs

therefore

ergo

has an easy-to-understand, but hard-to-find solution

obvious

has two easy-to-understand, but hard-to-find solutions

trivial

truth

tautology

empty

vacuous

drill problems

plug-and-chug work

criteria

rubric

example

substantive instantiation

similar structure

homomorphic

very similar structure

isomorphic

same area

isometric

arithmetic

number theory

count:

enumerate

one

unity

generally/specifically

globally/locally

constant

invariant

bonus result

corollary

distance

metric measure

several

a plurality

function/argument

operator/operand

separation/joining

bifurcation/confluence

fourth power or quartic

biquadratic

random

stochastic

unique condition

a singularity

uniqueness

unicity

tends to zero

vanishes

tip-top point

apex

half-closed

half-open

concave

non-convex

rectangular prisms

parallelepipeds

perpendicular (adj.)

orthogonal

perpendicular (n.)

normal

Euclid

Descartes

path

trajectory

shift

rectilinear translation

similar

homologous

very similar

congruent