SubtractFrom 
subtracts dx from x and returns the new value of x.
Details

- x-=dx is equivalent to x=x-dx.
- SubtractFrom has the attribute HoldFirst.
- In SubtractFrom[x,dx], x can be a symbol or other expression with an existing value. »
Examples
open allclose allBasic Examples (1)Summary of the most common use cases

https://wolfram.com/xid/09a8maemu-ikq58e


https://wolfram.com/xid/09a8maemu-d3oyff

Scope (4)Survey of the scope of standard use cases
Subtract from a numerical value:

https://wolfram.com/xid/09a8maemu-3mn70w

Subtract from a symbolic value:

https://wolfram.com/xid/09a8maemu-2dqqdg

Subtract from all values in a list:

https://wolfram.com/xid/09a8maemu-boaay


https://wolfram.com/xid/09a8maemu-2v76mu


https://wolfram.com/xid/09a8maemu-koraoz

The first argument to SubtractFrom need not be a symbol:

https://wolfram.com/xid/09a8maemu-5axyxt


https://wolfram.com/xid/09a8maemu-s6reew


https://wolfram.com/xid/09a8maemu-tck70d

Applications (1)Sample problems that can be solved with this function
Properties & Relations (3)Properties of the function, and connections to other functions
SubtractFrom is a short form of this assignment:

https://wolfram.com/xid/09a8maemu-5h1xz5

PreDecrement is a special case of SubtractFrom:

https://wolfram.com/xid/09a8maemu-lk1x9y


https://wolfram.com/xid/09a8maemu-fbnbxw

AddTo is closely related:

https://wolfram.com/xid/09a8maemu-c27up6


https://wolfram.com/xid/09a8maemu-hrn14p

Wolfram Research (1988), SubtractFrom, Wolfram Language function, https://reference.wolfram.com/language/ref/SubtractFrom.html.
Text
Wolfram Research (1988), SubtractFrom, Wolfram Language function, https://reference.wolfram.com/language/ref/SubtractFrom.html.
Wolfram Research (1988), SubtractFrom, Wolfram Language function, https://reference.wolfram.com/language/ref/SubtractFrom.html.
CMS
Wolfram Language. 1988. "SubtractFrom." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/SubtractFrom.html.
Wolfram Language. 1988. "SubtractFrom." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/SubtractFrom.html.
APA
Wolfram Language. (1988). SubtractFrom. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/SubtractFrom.html
Wolfram Language. (1988). SubtractFrom. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/SubtractFrom.html
BibTeX
@misc{reference.wolfram_2025_subtractfrom, author="Wolfram Research", title="{SubtractFrom}", year="1988", howpublished="\url{https://reference.wolfram.com/language/ref/SubtractFrom.html}", note=[Accessed: 11-May-2025
]}
BibLaTeX
@online{reference.wolfram_2025_subtractfrom, organization={Wolfram Research}, title={SubtractFrom}, year={1988}, url={https://reference.wolfram.com/language/ref/SubtractFrom.html}, note=[Accessed: 11-May-2025
]}