Chapter 2 briefly mentioned the stdin.getf function. What it left out of that discussion is where stdin.getf returns the floating-point value is reads from the standard input. Now that you've seen the floating-point extensions to the 80x86, it's possible to finish the discussion of that standard library function. The stdin.getf function reads a string of characters from the standard input, converts those characters to an 80-bit floating-point number, and leaves the result sitting on the FPU stack (in ST0).
The HLA Standard Library also provides the math.hhf module that includes several mathematical functions that the FPU doesn't directly support as well as support for various functions (like sine and cosine) that the FPU partially supports. Some of the functions that the math.hhf module provides are acos, acot, acsc, asec, asin, cot, csc, sec, 2x, 10x, yx, ex, log, and ln. Please consult the HLA standard library documentation for more information about these functions and other mathematical functions the HLA standard library supports.