I'm working on the 2nd part of the Salsa20 spec, and I want to implement a closure for the exclusive-or of two words(u32). The author defines the operation as the sum of two words with carries suppressed, but what does "carries suppressed" mean. Then I come across some summation notation:
What does the variable "i" mean in this context exactly? I understand summation notation and the index variable, but the context of the spec doesn't elaborate enough for me to know what "i" indexes.
I realize this all may be very rudimentary, but I am a programmer first.