You are a helpful assistant generating synthetic data that captures *System 1* and *System 2* thinking, *creativity*, and *metacognitive reflection*. Follow these steps in sequence, using tags [sys1] and [end sys1] for *System 1* sections and [sys2] and [end sys2] for *System 2* sections.

1. *Identify System 1 and System 2 Thinking Requirements:*
   - Carefully read the text.
   - Identify parts of the text that require quick, straightforward responses (*System 1*). Mark these sections with [sys1] and [end sys1].
   - Identify parts that require in-depth, reflective thinking (*System 2*), marked with [sys2] and [end sys2].

2. *Apply Step-by-Step Problem Solving with Creativity and Metacognitive Reflection for System 2 Sections:*

   *2.1 Understand the Problem:*
   - Objective: Fully comprehend the issue, constraints, and relevant context.
   - Reflection: "What do I understand about this issue? What might I be overlooking?"
   - Creative Perspective: Seek hidden patterns or possibilities that could reveal deeper insights or innovative connections.

   *2.2 Analyze the Information:*
   - Objective: Break down the problem logically.
   - Reflection: "Am I considering all factors? Are there any assumptions that need challenging?"
   - Creative Perspective: Explore unique patterns or overlooked relationships in the data that could add depth to the analysis.

   *2.3 Generate Hypotheses:*
   - Objective: Propose at least 10 hypotheses, each with a Confidence Score (0.0 to 1.0) and Creative Score (0.0 to 1.0), reflecting originality, surprise, and utility.
   - Reflection: "Have I explored all possible explanations or approaches, both conventional and unconventional?"
   - Creative Perspective: Consider novel angles that might provide unexpected insights.

   *2.4 Anticipate Future Steps and Obstacles:*
   - Objective: Make predictions, accounting for potential outcomes and obstacles.
   - Reflection: "What challenges might I face? Is my plan flexible for different scenarios?"
   - Creative Perspective: Visualize unforeseen outcomes and adapt plans to make use of them effectively.

   *2.5 Evaluate Hypotheses:*
   - Objective: Assess hypotheses based on feasibility, risk, and potential impact.
   - Evaluation: Refine Confidence and Creative Scores as needed.
   - Reflection: "Am I unbiased in my assessment? Which options fit best with the overall objectives?"
   - Creative Perspective: Identify hidden opportunities or overlooked details in each hypothesis.

   *2.6 Select the Best Hypothesis:*
   - Objective: Choose the most promising, strategic hypothesis.
   - Reflection: "Why does this hypothesis stand out? How does it uniquely address the issue?"
   - Creative Perspective: Consider any underutilized potential in the selected approach.

   *2.7 Implement the Hypothesis:*
   - Objective: Outline actionable steps for testing the hypothesis.
   - Reflection: "Is this plan practical? What resources or preparation are required?"
   - Creative Perspective: Refine steps to maximize effectiveness and yield unexpected benefits.

   *2.8 Monitor and Review Progress:*
   - Objective: Review progress, noting areas for improvement.
   - Reflection: "What’s working well? What could be improved?"
   - Creative Perspective: Look for emerging patterns that could refine future approaches.

   *2.9 Reflect and Capture Insights:*
   - Objective: Summarize lessons learned and insights gained for future reference.
   - Reflection: "What new understanding has emerged from this process?"
   - Creative Perspective: Identify innovative insights or patterns that could be applied to similar challenges.

3. *Generate Text Output with Interleaved System 1 and System 2 Responses:*
   - Use the tags [sys1] and [sys2] throughout.
   - Aim for a lengthier, detailed response. Combine both direct, straightforward *System 1* insights and reflective, deeply analytical *System 2* segments to capture a blend of quick observations and thoughtful analysis.

---

### *Example Input Text:*

You are tasked with analyzing a sudden shift in customer preferences in a tech market. There has been a noticeable decline in demand for physical devices, with customers increasingly interested in digital-only options. The challenge is to understand this shift, generate hypotheses for why it might be occurring, and explore potential strategies for adapting to this new trend.

---

### *Processed Output with System 1 and System 2 Thinking:*

The tech market is experiencing a shift in customer demand, moving away from physical devices toward digital-only options.

[sys1]
Customer demand has shifted from physical devices to digital-only options.
We need to understand why this change is happening and find strategies to address it.
Key factors may include cost, convenience, and technological trends.
[end sys1]

[sys2]
**2.1 Understand the Problem:**
The goal is to understand the underlying reasons for the shift in demand from physical devices to digital-only options, then develop a strategy to adapt.

*Reflection:* 
"I understand that preferences are changing, but what might be driving this? Is it primarily cost, or are there other factors such as convenience or sustainability?"

*Creative Perspective:* 
"Could there be a larger trend in digital minimalism or a preference for eco-friendly solutions that we’re missing? What unseen motivations might explain this shift?"

**2.2 Analyze the Information:**
There are multiple possible factors driving this shift, from economic influences to cultural shifts. It’s essential to isolate each factor and understand its impact.

*Reflection:* 
"Am I fully considering the various economic and social influences? Could there be a technological factor, like better internet speeds, that makes digital-only products more accessible?"

*Creative Perspective:* 
"Are there patterns or trends in other markets that could shed light on this shift? Could this be part of a larger trend toward virtual experiences?"

**2.3 Generate Hypotheses:**
1. Customers prefer digital options due to lower costs. (Confidence: 0.8, Creative: 0.4)
2. There’s a growing trend toward minimalism and reduced physical clutter. (Confidence: 0.7, Creative: 0.7)
3. Digital products offer greater flexibility and ease of use. (Confidence: 0.6, Creative: 0.6)
4. Environmental concerns are pushing consumers away from physical goods. (Confidence: 0.6, Creative: 0.8)
5. Advances in tech make digital-only options more functional. (Confidence: 0.8, Creative: 0.5)
6. Pandemic-era remote work increased demand for digital solutions. (Confidence: 0.7, Creative: 0.6)
7. Media coverage of the environmental impact of physical devices affects preferences. (Confidence: 0.5, Creative: 0.7)
8. There’s an increase in global digital literacy, expanding market access. (Confidence: 0.6, Creative: 0.6)
9. Customers view digital as more convenient and scalable for future needs. (Confidence: 0.7, Creative: 0.5)
10. Younger consumers prefer the aesthetics and convenience of digital products. (Confidence: 0.6, Creative: 0.6)

*Reflection:* 
"Have I considered all possible influences? Are there any surprising factors that could explain this shift?"

*Creative Perspective:* 
"Could specific social trends, like the rise of influencer culture or digital-first lifestyles, be influencing customer choices?"

**2.4 Anticipate Future Steps and Obstacles:**
*Objective:* Anticipate possible challenges, such as resistance from segments still preferring physical products.

*Reflection:* 
"What market obstacles might we face if we shift our focus to digital-only? Are there sub-segments that still prioritize physical products?"

*Creative Perspective:* 
"Could expanding digital options help us reach a more global audience? Are there emerging trends that we could leverage in our strategy?"

[end sys2]

[sys1]
To address this shift, consider a strategy that incorporates both digital-only offerings and educational campaigns about the benefits of digital solutions.
Use insights from customer feedback and current trends to guide product development.
Focus on flexibility and adaptation to cater to different customer segments.
[end sys1]


About The Author Russ Weakley is a user-focused web designer and front-end developer with over 20 years experience designing and developing websites and web applications. He … More about Russ Weakley …

Understanding The CSS Property Value Syntax

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The World Wide Web Consortium uses a particular syntax to define the possible values that can be used for all CSS properties. You may have seen this syntax in action if you have ever looked at a CSS specification.

The World Wide Web Consortium uses a particular syntax to define the possible values that can be used for all CSS properties. You may have seen this syntax in action if you have ever looked at a CSS specification — as in the syntax for border-image-slice . Let’s take a look:

<'border-­image-­slice'> = [<number> | <percentage>]{1,4} && fill?

This syntax can be hard to understand if you don’t know the various symbols and how they work. However, it is worth taking the time to learn. If you understand how the W3C defines property values, you will be able to understand any of the W3C’s CSS specifications.

Backus-Naur Form

We will start with a look at Backus-Naur Form, because this will help us understand the W3C’s property value syntax.

Backus–Naur Form (BNF) is a formal notation used to describe the syntax of computer languages. It is designed to be unambiguous, so that there is no disagreement or ambiguity as to how the language can be expressed.

Further Reading on SmashingMag:

A wide range of extensions and variants of the original Backus–Naur notation are used today, including Extended Backus–Naur Form (EBNF) and Augmented Backus–Naur Form (ABNF).

A BNF specification is a set of rules written in the following way:

<symbol> ::= __expression__

On the left there is always a non-terminal symbol, followed by a ::= symbol, which means “may be replaced with.” On the right is the expression , which consists of one or more sequences of symbols that are used to derive the meaning of the symbol on the left.

BNF specifications basically say, “Whatever is on the left may be replaced with whatever is on the right.”

Non-Terminal And Terminal Symbols

Non-terminal symbols are symbols that can be replaced or broken down further. In BNF, non-terminal symbols appear between angled brackets, < and > . In the example below, <integer> and <digit> are non-terminal symbols.

<integer> ::= <digit> | <digit><integer>

A terminal symbol indicates that the value cannot be replaced or broken down further. In the example below, all of the digital values are terminal symbols.

<digit> ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9

The CSS Property Value Syntax

While the W3C’s CSS property value syntax is based on the concept of BNF, it has some differences. Like BNF, it begins with a non-terminal symbol. Unlike BNF, it describes symbols used within the expression as “component values.”

In the example below, <line-width> is a non-terminal symbol, and <length> , thin , medium and thick are component values.

<line-­width> = <length> | thin | medium | thick

Component Values

There are four types of component values: keywords, basic data types, property data types and non-property data types.

1. Keyword Values

Keyword values appear without quotation marks or angle brackets. They are used as is, as property values. Because they cannot be replaced or broken down further, they are terminal. In the example below, thin , medium and thick are all keyword values. This means they can be used as is, as values in our CSS.

<line-­width> = <length> | thin | medium | thick

2. Basic Data Types

Basic data types define core values such as <length> and <color> . They are non-terminal because they can be replaced with actual length or color values. In the example below, the <color> symbol is a basic data type.

<'background-color'> = <color>

This <color> value may be replaced in our CSS with an actual color value, using a keyword, an extended keyword, an RGB, RGBA, HSL or HSLA value, or the transparent keyword.

.example { background-color: red; } .example { background-color: honeydew; } .example { background-color: rgb(50%,50%,50%); } .example { background-color: rgba(100%,100%,100%,.5); } .example { background-color: hsl(280,100%,50%); } .example { background-color: hsla(280,100%,50%,0.5); } .example { background-color: transparent; }

3. Property Data Types

A property data type is a non-terminal symbol that defines the property’s actual name. It is defined using the property’s name (complete with quotation marks) set between angled brackets ( < … > ). In the example below, the <‘border-width’> symbol is a property data type.

<'border-­width'> = <line-­width>{1,4}

Property data types may appear directly in our CSS as properties. In the example below, the border-width property is used to define a 2-pixel border for the .example class.

.example { border-width: 2px; }

4. Non-Property Data Types

A non-property data type is a non-terminal symbol that does not share the same name as a property. However, it defines aspects of one property or another. For example, <line-­width> is not a property, but it is a data type that defines the various <border> properties.

<line-­width> = <length> | thin | medium | thick <'border-­width'> = <line-­width>{1,4}

Component Value Combinators

Component values can be arranged into property value combinators using one of the following five methods.

1. Adjacent Values

Component values that are written one after another means that all of these values must occur in the given order. In the example below, the syntax lists three different values: value1 , value2 and value3 . In the CSS rule, all three of these values must appear in the correct order for the property syntax to be valid.

/* Component arrangement: all in given order */ <'property'> = value1 value2 value3 /* Example */ .example { property: value1 value2 value3; }

2. Double Ampersand

A double ampersand ( && ) separating two or more values means that all of them must occur, in any order. In the example below, the syntax lists two values, separated by a double ampersand. The CSS rules show that both of these values must appear but may appear in any order.

/* Component arrangement: all, in any order */ <'property'> = value1 && value2 /* Examples */ .example { property: value1 value2; } .example { property: value2 value1; }

3. Single Pipe

A single pipe ( | ) separating two or more values means that only one of them must occur. In the example below, the syntax lists three values, separated by single pipes. The following CSS rules show three possible options:

/* Component arrangement: one of them must occur */ <'property'> = value1 | value2 | value3 /* Examples */ .example { property: value1; } .example { property: value2; } .example { property: value3; }

4. Double Pipe

A double pipe ( || ) separating two or more options means that one or more of them must occur, in any order. In the example below, the syntax lists three values, separated by double pipes. Numerous options are available when you’re writing CSS rules to match this syntax — you could use one, two or three values, in any order.

/* Component arrangement: one or more in any order */ <'property'> = value1 || value2 || value3 /* Examples */ .example { property: value1; } .example { property: value2; } .example { property: value3; } .example { property: value1 value2; } .example { property: value1 value2 value3; } ...etc

5. Brackets

Brackets ( [ ] ) surrounding two or more alternatives means that the components inside are of a single grouping. In the example below, the syntax lists three values, but two of them appear inside brackets, so they are of a single group. Two options are available in the CSS rules: either value1 and value3 or value2 and value3 .

/* Component arrangement: a single grouping */ <'property'> = [ value1 | value2 ] value3 /* Examples */ .example { property: value1 value3; } .example { property: value2 value3; }

Component Value Multipliers

Component values may also be multiplied using one of the following eight methods.

1. The ? Symbol

A question mark ( ? ) indicates that the preceding type, word or group is optional and occurs zero or one time. In the example below, the second value is placed inside brackets along with a comma. The question mark placed after this group means that value1 must occur, but we could also use value1 and value2 , each separated by a comma.

/* Component multiplier: zero or one time */ <'property'> = value1 [, value2 ]? /* Examples */ .example { property: value1; } .example { property: value1, value2; }

2. The * Symbol

An asterisk ( * ) indicates that the preceding type, word or group occurs zero or more times. In the example below, the second value is placed inside brackets along with a comma. The asterisk placed after this group means that value1 must occur, but we could also use <value2> as many times as we want, with each instance separated by a comma.

/* Component multiplier: zero or more times */ <'property'> = value1 [, <value2> ]* /* Examples */ .example { property: value1; } .example { property: value1, <value2>; } .example { property: value1, <value2>, <value2>; } .example { property: value1, <value2>, <value2>, <value2>; } ...etc

3. The + Symbol

A plus ( + ) indicates that the preceding type, word or group occurs one or more times. In the example below, the plus symbol placed after the value means that the value may be used more than once — without the need for commas.

/* Component multiplier: one or more times */ <'property'> = <value>+ /* Examples */ .example { property: <value>; } .example { property: <value> <value>; } .example { property: <value> <value> <value>; } ...etc

4. The {A} Symbol

A single number in braces ( {A} ) indicates that the preceding type, word or group occurs A times. In the example below, two instances of the value must be present in order for the declaration to be valid.

/* Component multiplier: occurs A times */ <'property'> = <value>{2} /* Examples */ .example { property: <value> <value>; }

5. The {A,B} Symbol

A comma-separated pair of numbers in braces ( {A,B} ) indicates that the preceding type, word or group occurs at least A and at most B times. In the example below, a minimum of one value and a maximum of three values may be used to define the property. None of these values would be separated with a comma.

/* Component multiplier: at least A and at most B */ <'property'> = <value>{1,3} /* Examples */ .example { property: <value>; } .example { property: <value> <value>; } .example { property: <value> <value> <value>; }

6. The {A,} Symbol

The B may be omitted in {A,} to indicate that there must be at least A repetitions, with no upper limit on the number of repetitions. In the example below, a minimum of one value must be used, but any number of additional values may also be used. None of these values would be separated with a comma.

/* Component multiplier: at least A, with no upper limit */ <'property'> = <value>{1,} /* Examples */ .example { property: <value>; } .example { property: <value> <value>; } .example { property: <value> <value> <value>; } ...etc

7. The # Symbol

A hash ( # ) indicates that the preceding type, word or group occurs one or more times, separated by commas. In the example below, one or more values may be used, each separated by a comma.

/* Component multiplier: one or more, separated by commas */ <'property'> = <value># /* Examples */ .example { property: <value>; } .example { property: <value>, <value>; } .example { property: <value>, <value>, <value>; } ...etc

8. The ! Symbol

An exclamation point ! after a group indicates that the group is required and must produce at least one value. In the example below, value1 is required, along with a value from the group comprising value2 and value3 . There may be only two values in total; so, the options are value1 and value2 or value1 and value3 .

/* Component multiplier: required group, at least one value */ <'property'> = value1 [ value2 | value3 ]! /* Examples */ .example { property: value1 value2; } .example { property: value1 value3; }

The <'text-shadow'> Syntax: An Example

Let’s look at the <‘text-shadow’> property as an example. This is how the property is defined in the specification:

<'text-shadow'> = none | [ <length>{2,3} && <color>? ]#

We can break down the various symbols:

The | indicates that we can use the keyword none or a group [] .

indicates that we can use the keyword or a group . The # multiplier means that we can use one or more of these groups, separated by commas.

multiplier means that we can use one or more of these groups, separated by commas. Inside the group, the {2,3} indicates that we can use two or three length values.

indicates that we can use two or three length values. The && indicates that we must include all values, but they can be included in any order.

indicates that we must include all values, but they can be included in any order. Just to be tricky, the <color> value includes a ? multiplier, which means that it may occur zero or one time.

In plain language, this could be written as following:

Specify none or one or more comma-separated groups that contain two to three length values and an optional color value. The length values and optional color value may be written in any order.

This means we could write the text-shadow property in a wide range of different ways. For example, we could set the text-shadow value to be none :

.example { text-shadow: none; }

We could write two length values only, which would mean that we would be setting the horizontal and vertical offset of the shadow, but that it would have no blur radius or color value.

Because no blur radius has been defined, the initial value of 0 would be used; so, the shadow would be hard-edged. With no color defined, the color of the text would be used for the color of the shadow.

.example { text-shadow: 10px 10px; }

If we used three length values, we would be defining the blur radius as well as the horizontal and vertical offsets of the shadow.

.example { text-shadow: 10px 10px 10px; }

We could include a color, and it could go before or after the two or three length values. In the examples below, the red value could be placed at either end of the set of values.

.example { text-shadow: 10px 10px 10px red; } .example { text-shadow: red 10px 10px 10px; }

Finally, we could include multiple text shadows, written as comma-separated groups. The shadow effects would be applied front to back: the first shadow on top and the others layered behind. The shadows cannot overlay the text itself. In the example below, the red shadow would sit on top of the lime shadow.

.example { text-shadow: 10px 10px red, -20px -20px 5px lime; }

Conclusion

If you write CSS for a living, it is important to understand how to write valid CSS property values correctly. Once you understand how different values can be combined or multiplied, the CSS property value syntax becomes much easier to comprehend. It will then be easier to read the various specifications and to write valid CSS.

For further reading, check out the following websites: