Overview > Operations > Conversion is impossible example giving different results

[SukhbirChung]

@incompatible-units: 2 + 5px - 3cm; // result is 4px

The docs state that the result is 4 px ( 2 + 5 = 7px minus cm ignored gives (7px - 3cm = 4px)). However, the result is different. For example,
p {
margin-left: 2 + 5px - 3cm;
}

According to the docs, the left margin must be 4px that is the paragraph content must be moved 4px to the right. However, the observed behaviour is: Paragraph content is moved 7px to the right and then 3cm to the left.