PART I
Warm-up
Reconnect with a useful idea before starting values, expressions, and arithmetic. In one or two sentences, describe the input, output or host boundary from the previous exercise that this lesson builds on. If you are arriving directly, skim the worked example first; there is no locked prerequisite.
A rough note is enough. You can revise it after the example.
PART II
Instruction & guided example
Compare two equivalent forms using meaningful cases
Different expressions can describe the same rule. To compare alternatives, identify a shared input domain, explain the algebra, and use cases that exercise the parts of the formula. A few examples support understanding but do not establish every implementation detail of a proposed language.
For two identical items plus a fee, price * 2 + fee and price + price + fee express the same mathematical rule. At price 60 and fee 15, the first computes 120 + 15 = 135; the second computes 60 + 60 + 15 = 135. At price 0, both leave the fee; at fee 0, both leave two prices.
The expression (price + fee) * 2 is not an equivalent form: it doubles the fee. Using fee zero would hide the defect, so retain a nonzero fee case. Keep claims bounded to ordinary inputs where overflow or other unresolved numeric behavior is irrelevant.
Worked reasoning and supplied artifact
fnc totalA(price: i32, fee: i32) -> i32 {
return price * 2 + fee;
}
fnc totalB(price: i32, fee: i32) -> i32 {
return price + price + fee;
}Illustrative example from the proposed WillowScript design. The language and WUIX/WMATH/WDB/WAUDIO/WTMP services are not implemented in the supplied source. This site has no interpreter, VM or native host and does not execute or certify the snippet.
Walk through the example, one line at a time
fnc totalA(price: i32, fee: i32) -> i32 {Read the function name, its parameter names/types and the result type after ->. This is the contract the body must satisfy.
return price * 2 + fee;Evaluate the following expression using the current values, then send its result to the caller. Explain the value; do not confuse it with printed output.
}Close the nested block or value begun earlier. Match it to its opening boundary to keep the structure readable.
fnc totalB(price: i32, fee: i32) -> i32 {Read the function name, its parameter names/types and the result type after ->. This is the contract the body must satisfy.
return price + price + fee;Evaluate the following expression using the current values, then send its result to the caller. Explain the value; do not confuse it with printed output.
}Close the nested block or value begun earlier. Match it to its opening boundary to keep the structure readable.
Try the guided change
Trace both helpers at (60,15), (0,15) and (60,0). Explain the repeated quantity in words.
- Write the supplied inputs and initial state before following the example.
- Reconstruct each intermediate calculation or host decision, then compare with the worked artifact.
- Explain why the contrasting alternative fails before attempting the changed inputs in Part IV.
PART III
Take a breather
Step back after the guided example. Look away from the screen, stretch, or reread your prediction. This is an optional learning pause, not a timer or an assessment gate.
When you return, try to name the lesson’s key idea without copying its wording. If that feels difficult, return to Part II and trace one line rather than restarting the entire lesson.
PART IV
Independent practice
Project context: Snack-shop calculator. Build a small, understandable change around values, expressions, and arithmetic.
Propose two equivalent expressions for three identical reward bundles and one fixed bonus. Compare them with a wrong expression that triples the bonus too; choose an input that exposes the error.
What to produce
Two valid formulas, one counterexample against the wrong formula, and a bounded equivalence explanation.
- State the intended behavior in a sentence before editing.
- Use only source-backed syntax and the host services whose contract you have been given.
- Record a normal case and a boundary or unavailable-resource case.
- Label hand predictions separately from anything actually measured in a supplied toolchain.
Syntax colors are a reading aid, not a compiler. The line you are editing stays uncolored until you move to a different line; capitalization is never changed. Drafts stay on this browser and code is not executed.
Need a hint?
For two identical items plus a fee, price * 2 + fee and price + price + fee express the same mathematical rule. At price 60 and fee 15, the first computes 120 + 15 = 135; the second computes 60 + 60 + 15 = 135. At price 0, both leave the fee; at fee 0, both leave two prices.
The expression (price + fee) * 2 is not an equivalent form: it doubles the fee. Using fee zero would hide the defect, so retain a nonzero fee case. Keep claims bounded to ordinary inputs where overflow or other unresolved numeric behavior is irrelevant.
Original learning-path task and reference
In a museum exhibit console, demonstrate values, expressions, and arithmetic. Produce an equivalent approach and justify why both implementations satisfy the same contract. Include .ws source and a host-resource contract; compare at least one normal case and one edge case.
fnc add(a: i32, b: i32) -> i32 {
return a + b;
}
fnc main() -> i32 {
return add(2, 3);
}Where the original task needs a host API that is not supplied here, write the contract and predictions. Do not invent a runtime result.
PART V
Self-check
Use this check to notice what to revisit. It does not award a private course grade, block another page or claim to verify compiled code. Every answer has a learning explanation.
You may keep exploring even if you are unsure. Use the hint, compare the trace, and revise your explanation.
PART VI
Recap & small task
Bring the idea back to the mod feature you are building. A useful recap connects the mechanism to a decision you can make in your own code.
- Compare two equivalent forms using meaningful cases
- Different expressions can describe the same rule. To compare alternatives, identify a shared input domain, explain the algebra, and use cases that exercise the parts of the formula. A few examples support understanding but do not establish every implementation detail of a proposed language.
- Separate source-backed behavior, host requirements and untested predictions.
One small recap task
Write one sentence explaining why examples alone are weaker than an algebraic argument.
This marks your personal practice record only. It is not a certification or an official workspace assessment.