some simple functions:
p3(x) = { x*(x+1)/2 }
p4(x) = { x*x }
p5(x) = { x*((3*x)-1)/2 }
p6(x) = { x*((2*x)−1) }
p7(x) = { x*(5*x−3)/2 }
p8(x) = { x*(3*x−2) }
unexpected results:
GP/PARI CALCULATOR Version 2.7.5 (released)
amd64 running linux (x86-64/GMP-6.1.0 kernel) 64-bit version
compiled: Jan 27 2016, gcc version 4.9.3 (GCC)
threading engine: single
? p3(x) = { x*(x+1)/2 }
%1 = (x)->x*(x+1)/2
? p4(x) = { x*x }
%2 = (x)->x*x
? p5(x) = { x*((3*x)-1)/2 }
%3 = (x)->x*((3*x)-1)/2
? p6(x) = { x*((2*x)−1) }
*** syntax error, unexpected $undefined, expecting )-> or ',' or ')': p6(x)=x*((2*x)−1)
*** ^-
? p7(x) = { x*(5*x−3)/2 }
*** syntax error, unexpected $undefined, expecting )-> or ',' or ')': p7(x)=x*(5*x−3)/2
*** ^---
? p8(x) = { x*(3*x−2) }
*** syntax error, unexpected $undefined, expecting )-> or ',' or ')': p8(x)=x*(3*x−2)
*** ^-
?