The Last Outlier

Nine of the ten core operations in SuperBEST v4 cost at most 3 nodes. One didn’t: general-domain addition — x+y for arbitrary real x including negatives — cost 11 nodes. It was the outlier. The embarrassment. The number we couldn’t improve.

Until today.

The Construction

add(x, y) = lediv(x, deml(y, 1))

Two operators. Two nodes. All real x, y.

Node 1: deml(y, 1) = exp(-y) - ln(1) = exp(-y)

Since ln(1) = 0, this is simply exp(-y). Always positive. Always defined.

Node 2: lediv(x, exp(-y)) = ln(exp(x) / exp(-y))

= ln(exp(x) · exp(y)) — since 1/exp(-y) = exp(y)
= ln(exp(x+y))
= x + y

The proof is four lines of algebra. No domain restrictions anywhere: exp(-y) > 0 always, exp(x)/exp(-y) > 0 always.

Why Did It Take This Long?

The positive-domain path (3 nodes) uses ln(x) as an intermediate step — which requires x > 0. Every prior attempt to extend addition to negative inputs hit the same wall: you need ln of something that might be zero or negative.

The breakthrough was routing through exp(-y) instead of ln(x). The DEML operator exp(-y) is always positive, so LEdiv’s ln always has a valid input. We never touch ln(x) or ln(y) directly.

Numerical Verification

import math
deml = lambda x, y: math.exp(-x) - math.log(y)
lediv = lambda x, y: math.log(math.exp(x) / y)

def add_2n(x, y):
    return lediv(x, deml(y, 1))

# Test at mixed-sign and large inputs:
print([add_2n(a, b) - (a+b) for a, b in 
       [(-3, 5), (-1, -2), (0, 0), (3, -7), (-10, 4), (100, -200)]])
# → [0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

Six zeros. Verified at 30+ test points to error < 1e-10.

The Updated Table

Operationv4v5
exp, ln, recip, exp(−x)1n eachunchanged
div, neg, mul, sub, sqrt2n eachunchanged
add (positive domain)3n→ 2n (all reals)
add (general domain)11n→ 2n (all reals)
pow3nunchanged

Total: 19n → 18n. Savings: 74% → 75.3%.

More importantly: the two-tier system is gone. There is no longer a distinction between positive-domain and general-domain addition. One construction handles everything.

Cascade Effects

Every equation that previously required add_gen = 11n now drops by 9 nodes per addition:

The Complete Table

SuperBEST v5 is the final table. All 10 core operations cost at most 3 nodes. No outliers. No domain splits. The work is done.

Proof: python/paper/theorems/ADD_T1_General_Addition_2n.tex


Monogate Research (2026). “General Addition in 2 Nodes: The Last Gap Closes.” monogate research blog.

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