I'll work through this step-by-step, analyzing REN's financial data and applying S&P's methodology.

## Step 1: Identify the Relevant Industry

REN - Redes Energéticas Nacionais is Portugal's national electricity and gas transmission network operator. This is a **regulated utility** (specifically, electricity and gas transmission/distribution). The company operates under regulated tariffs with concession agreements for energy infrastructure.

Key characteristics:
- Electricity national transmission and gas network operator
- Regulated utility with concession framework
- Natural monopoly with regulatory oversight

## Step 2: Estimate 2021 Adjusted_EBITDA

First, I need to reconstruct EBITDA from the available data.

For 2021 (period 2021-01-01 to 2022-01-01):
- Revenue and Operating Income: 838,353,000 EUR
- Operating Expense: 619,490,000 EUR
- Profit/Loss from Operating Activities: 218,863,000 EUR

Let me verify: Revenue and Operating Income (838,353,000) - Operating Expense (619,490,000) = 218,863,000 ✓

EBITDA = Profit from Operating Activities + Depreciation and Amortization
- Depreciation and Amortization Expense: 241,940,000 EUR

EBITDA = 218,863,000 + 241,940,000 = **460,803,000 EUR**

For regulated utilities, S&P notes they use ROE for cost-of-service utilities, but we need EBITDA for leverage metrics. Let me check if adjustments are needed:

Looking at the data:
- No lease adjustments mentioned explicitly
- No nonrecurring items clearly identified
- No pension adjustments needed for EBITDA calculation
- The "Revenue Recognised On Exchanging Construction Services For Intangible Asset" (237,696,000 EUR) is part of normal regulated utility operations (construction work in progress)

For regulated utilities, S&P mentions they don't adjust for regulatory accounting effects. The construction services for intangible assets are typical for concession-based utilities.

Adjusted_EBITDA_2021 = **460,803,000 EUR**

## Step 3: Estimate 2021 FFO

FFO = Adjusted_EBITDA - cash_interest - cash_taxes

From cash flow statement:
- Interest Paid (financing activities): 39,725,000 EUR
- Income Taxes Paid (operating activities): 74,253,000 EUR

However, for FFO calculation, we need interest paid from operations. Looking at the P&L:
- Finance Costs: 54,356,000 EUR
- Other Finance Income: 3,272,000 EUR
- Revenue from Dividends: 8,496,000 EUR
- Finance Income/Cost net: -42,588,000 EUR (negative means net cost)

For cash interest, I'll use the cash flow statement's interest paid in financing activities: 39,725,000 EUR. However, S&P typically uses cash interest paid. Let me check if there's any capitalized interest.

Actually, looking more carefully at cash flows: "Interest Paid Classified As Financing Activities" = 39,725,000 EUR

FFO = 460,803,000 - 39,725,000 - 74,253,000 = **346,825,000 EUR**

Wait - let me reconsider. S&P's FFO formula typically adds back working capital changes. Let me re-read: "FFO = Adjusted_EBITDA - cash_interest - cash_taxes"

This seems straightforward. But I should verify if we need to use cash taxes from operations or tax expense. The formula says "cash_taxes", so I'll use the cash flow figure.

FFO_2021 = 460,803,000 - 39,725,000 - 74,253,000 = **346,825,000 EUR**

## Step 4: Estimate 2021 Adjusted_Debt

Adjusted_Debt = reported_debt + leases + pension_deficit + guarantees + hybrid_debt_portion + other_debt_like_items - eligible_cash

From balance sheet (2022-01-01, which is end of 2021):
- Long-term Borrowings: 2,390,852,000 EUR
- Current Borrowings and Current Portion of Noncurrent Borrowings: 375,221,000 EUR

Total reported debt = 2,390,852,000 + 375,221,000 = 2,766,073,000 EUR

For regulated utilities, S&P mentions:
- Purchased power contracts with debt-like obligations (not relevant for transmission)
- Seasonal working capital adjustments (net inventory against short-term borrowings) - not clearly needed here
- Securitized debt deconsolidation - not mentioned

Looking for other items:
- Noncurrent Provisions For Employee Benefits: 94,109,000 EUR (pension/employee benefits - this is a debt-like item)
- Current Tax Liabilities: 26,644,000 EUR (not debt-like for this purpose)
- Trade payables are operating, not debt-like

Leases: Not explicitly broken out. "Payments Of Lease Liabilities Classified As Financing Activities" = 2,065,000 EUR, and "Payments Of Lease Interests" = 29,000 EUR. This suggests leases exist but are relatively small. Without explicit lease liability, I'll note this but may not have precise data.

Cash and Cash Equivalents: 398,759,000 EUR

For eligible cash, S&P typically uses unrestricted cash. Given this is a regulated utility with stable cash flows, I'll consider most cash as eligible, but may haircut some.

Adjusted_Debt_2021 = 2,766,073,000 + 94,109,000 (pension) - 398,759,000 (cash) = **2,461,423,000 EUR**

Let me reconsider: The employee benefits provision may include both pensions and other post-employment benefits. This is a reasonable proxy for pension deficit.

## Step 5: Calculate 2021 Adjusted_Debt / Adjusted_EBITDA

= 2,461,423,000 / 460,803,000 = **5.34x**

## Step 6: Calculate 2021 FFO / Adjusted_Debt

= 346,825,000 / 2,461,423,000 = **0.141 or 14.1%**

## Step 7: Estimate 2022 Adjusted_EBITDA

For 2022 (period 2022-01-01 to 2023-01-01):
- Profit/Loss from Operating Activities: 239,721,000 EUR
- Depreciation and Amortization Expense: 249,276,000 EUR

EBITDA = 239,721,000 + 249,276,000 = **488,997,000 EUR**

Adjusted_EBITDA_2022 = **488,997,000 EUR**

## Step 8: Estimate 2022 FFO

- Interest Paid (financing activities): 40,545,000 EUR
- Income Taxes Paid (operating activities): 77,970,000 EUR

FFO_2022 = 488,997,000 - 40,545,000 - 77,970,000 = **370,482,000 EUR**

## Step 9: Estimate 2022 Adjusted_Debt

From balance sheet (2023-01-01, which is end of 2022):
- Long-term Borrowings: 1,695,362,000 EUR
- Current Borrowings and Current Portion of Noncurrent Borrowings: 638,944,000 EUR

Total reported debt = 1,695,362,000 + 638,944,000 = 2,334,306,000 EUR

Other items:
- Noncurrent Provisions For Employee Benefits: 64,939,000 EUR
- Cash and Cash Equivalents: 365,292,000 EUR

Note: There's a significant change in debt structure - long-term debt decreased while current debt increased. This suggests refinancing activity.

Also important: The "Asset Related To The Transitional Gas Price Stabilization Regime" and corresponding liability. This is a regulatory mechanism related to gas price stabilization (Decree-Law 84-D/2022). This is a regulatory asset/liability that should net out.

Adjusted_Debt_2022 = 2,334,306,000 + 64,939,000 - 365,292,000 = **2,033,953,000 EUR**

Wait - I need to consider the transitional gas price stabilization regime. This created both a 1,000,000,000 EUR asset and liability. For credit analysis, this is essentially a pass-through mechanism. The liability is not really debt-like in the traditional sense - it's a regulatory balancing account. However, S&P's methodology says they focus on economics and actual cash flow generation.

Looking more carefully: This regime was established by Decree-Law 84-D/2022 and relates to transitional gas price stabilization. This is likely a mechanism where REN collects/fees that are passed through. The liability represents amounts to be returned or settled.

For conservative credit analysis, I should consider whether this liability is debt-like. Given it's a regulatory pass-through mechanism, it may not represent true economic debt. However, if it's a payable that must be settled, it could be considered.

Let me check if this affects operating cash flow: "Other Inflows Outflows Of Cash Classified As Operating Activities" was -51,733,000 in 2022 vs -61,427,000 in 2021. Not dramatically different.

I'll be conservative and exclude this regulatory liability from debt, as it appears to be a pass-through mechanism (similar to how S&P treats certain regulatory accounts).

## Step 10: Calculate 2022 Adjusted_Debt / Adjusted_EBITDA

= 2,033,953,000 / 488,997,000 = **4.16x**

## Step 11: Calculate 2022 FFO / Adjusted_Debt

= 370,482,000 / 2,033,953,000 = **0.182 or 18.2%**

## Step 12: Classify Year-on-Year Credit Trend

**Signal 1: Leverage (Adjusted_Debt / Adjusted_EBITDA)**
- 2021: 5.34x
- 2022: 4.16x
- Change: 4.16 - 5.34 = **-1.18x**

This is ≤ -0.2x, so **Improving**

**Signal 2: Cash-flow coverage (FFO / Adjusted_Debt)**
- 2021: 0.141
- 2022: 0.182
- Change: 0.182 - 0.141 = **+0.041**

This is ≥ +0.03, so **Improving**

Both signals agree: **Improving**

Let me verify my calculations and consider if I need to adjust anything:

Key drivers of improvement:
1. Debt restructuring: Long-term borrowings decreased from 2,390,852,000 to 1,695,362,000, while current portion increased. This suggests debt maturity management but overall debt decreased.
2. EBITDA improved: 460,803,000 to 488,997,000 (up ~6%)
3. FFO improved: 346,825,000 to 370,482,000 (up ~7%)
4. Net debt decreased significantly due to lower overall borrowings and the cash position being relatively stable

Wait - let me re-check the debt. Total borrowings 2021: 2,390,852,000 + 375,221,000 = 2,766,073,000. Total borrowings 2022: 1,695,362,000 + 638,944,000 = 2,334,306,000. This is a decrease of 431,767,000 in gross debt.

However, looking at cash flows from financing:
- Proceeds from borrowings: 1,165,000,000
- Repayments: 1,523,313,000
- Net: -358,313,000

This is consistent with debt reduction.

The improvement in leverage is quite significant (from 5.34x to 4.16x), driven by both EBITDA growth and debt reduction. The FFO coverage improvement is also meaningful (from 14.1% to 18.2%).

One consideration: The 2022 balance sheet includes the transitional gas price stabilization asset/liability. If I were to include the liability in debt, Adjusted_Debt_2022 would be 3,033,953,000, giving leverage of 6.20x and FFO coverage of 12.2%, which would show deterioration. However, this is a regulatory balancing account that should net against the asset. The S&P methodology emphasizes economics and cash flow generation, and this item doesn't represent true economic debt - it's a pass-through mechanism where REN is essentially a collection/distribution agent.

Given the explicit matching of asset and liability at 1,000,000,000 EUR each, and the regulatory nature of this mechanism, excluding it from adjusted debt is appropriate.

Both signals clearly show Improving, and they agree.

<answer>Improving</answer>