Coming soon to Actilud. Once the programming instructions are entered, you must generate the formal propositions, that is, the statements that make up the puzzle. These statements are “formal” because they are written symbolically, using signs, which you will need to translate into everyday language. The generation of formal proposals depends, of course, first and foremost […]
Places a true or false sign at the intersection of a row and a column. This is the basic instruction of zebra puzzles. Alice is third. Bob is wearing a yellow jersey. Fifth doesn’t drink apple juice. When a true sign is placed, the row and column of the intersection can be completed with false […]
The threshold instruction compares a subject to a value in an ordered series. It randomly sets a threshold in the series, beyond which values are false. This is an easy instruction, recommended for simple zebra puzzles. To use it, at least one ordered series is required. The threshold instruction does not require the series to […]
Make a vague comparison between two items a and b sharing a common ordered series. This instruction is one of the few that cannot use Booleans; it requires a traditional resolution: returning to the statement several times. This is why this type of comparison is called vague. The common ordered series does not need to […]
Establishes a precise anteriority relationship between two items a and b, both using a series C containing an order relationship. The series C allows to indicate a constant distance d, which appears between a and b. To use it, you therefore need at least one ordered series. The series does not need to be regular. […]
Establishes a precise anteriority relation between three items a, b, c, all three using a series D containing an order relation. The series D allows to indicate two constant distances d 1 and d 2 , which appear between a and b for d 1 , b and c for d 2 . To use […]
Create a gap between two items a and b using a regular ordered series. To use it, you therefore need at least one regular ordered series. To make solving easier, Booleans are recommended. This is one of the most complex instructions in zebra puzzles. Ordered series: A series containing values that are all increasing or […]
Creates an alternative regarding a given topic. The alternative can take place in a single grid or across two grids. When the alternative concerns a single grid, there is no need to use Booleans: false signs are sufficient. When it concerns several grids, Booleans must be used with the grid of alternatives. The alternatives translate […]
Performs a sum s of the items chosen from two summable series A and B. If there are more than 2 summable series, they will be drawn randomly. The SUM instruction allows you to choose the subject heading. To use it, you therefore need at least two summable series. To facilitate resolution, Booleans are recommended. […]
Perform a sum s of the items chosen from all summable series. At least two are required. The subject is chosen from the remaining series. The TOTAL instruction may require waiting until the boxes are more or less filled before using the Booleans. Indeed, it may not be usable from the beginning of the puzzle, […]
Coming soon to Actilud. Article under construction. Applies a mathematical formula. The formula can be applied to all calculable values. f(a,b,c) = a * (cb) Since the May 2026 update, the SUM, TOTAL, THRESHOLD instructions use the FORMULA instruction. This instruction was programmed to allow the creation of original puzzles, such as the stock market game on […]
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