Future Value (Lump Sum) implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

live-source boundary

Effect

Computation or source lookup only

Input and validation requirements

The n=0 vector produces an undefined division by zero. The instrument should reject n=0 before evaluating the formula; accepting it would create an undefined result or implementation-dependent behavior.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "PV": 1000,
    "r": 0.08,
    "n": 4,
    "t": 2
  },
  "expected_outputs": {
    "FV": 1171.659381004512,
    "total_growth": 171.659381004512
  },
  "working": "Periodic rate = r/n = 0.08/4 = 0.02. Total periods = n*t = 4*2 = 8. Growth factor = (1+0.02)^8 = 1.02^8 = 1.171659381004512. FV = 1000*1.171659381004512 = 1171.659381004512. Total growth = FV-PV = 1171.659381004512-1000 = 171.659381004512."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche2/batch10-output.jsonl