Thank you so much for the reply everyone. I really appreciate it.
Sorry if i didnot explain enough.
Basically i want to control two stepper at the same time. I will input the speed and acceleration at the void loop, through the ctrl+shift+m page. I can control one now . However i want the option to decelerate like the acceleration. It start with x step/s then decrease slowly to y step/s (minimum speed)
Hacking the library itself is also a challange for me since i am still begineer in arduino programming.