For a_n=3-2/(n+1), prove monotonicity, boundedness, supremum 3 and convergence.
A full n≥0 law with a strict epsilon certificate; explicitly include the general theorem's supremum step.
Givens and symbols
algebra
epsilon
supremum
definition_here
G1 — a_n=3-2/(n+1) for every n≥0; use the least-upper-bound property of R.
a_n — concrete whole sequence
s — general theorem supremum
Rules and sources
Some rule statements have reader clarifications in this revision: they are paraphrases, not verbatim quotations. Referenced original source bytes and hashes are unchanged.
mko_definition · cited — Keep whole-sequence monotonicity and the corresponding bound. If s is the supremum of the terms, s−epsilon is not an upper bound, supplying an index N; monotonicity then controls every later term. A supremum or infimum need not be a term. A finite prefix does not supply a universal certificate. A monotone sequence without the required bound, or a bounded sequence lacking monotonicity, does not meet this theorem's hypotheses. · mko-monotone-sequence-convergence-theorem
algebra · prerequisite — Use real-field identities; division requires a nonzero denominator and multiplication by a positive number preserves inequalities.
epsilon · prerequisite — Convergence requires for every positive epsilon an integer N controlling every n≥N by a strict error bound; use the Archimedean property of the reals.
supremum · prerequisite — A nonempty bounded-above real set has supremum s; for epsilon>0, s-epsilon is not an upper bound.
definition_here · prerequisite — The epsilon definition of real-sequence limit L requires, for each positive epsilon, an N with |u_n-L|<epsilon for every n≥N.
Main derivation
S01 · implies
Before
a_{n+1}-a_n=2/(n+1)-2/(n+2)
After
a_{n+1}-a_n=2/((n+1)(n+2))>0
Conditions: n\ge0
Rule: algebra · Uses: G1
Leaf basis: algebra
Both denominators are positive, proving every adjacent difference positive and hence whole-sequence strict increase.
S02 · implies
Before
0<2/(n+1)\le2
After
1\le a_n<3
Conditions: none
Rule: algebra · Uses: G1
Leaf basis: algebra
This gives lower bound 1 and the upper bound 3 needed for the increasing-sequence theorem.