### Abstract

We obtain the first non-trivial time-space tradeoff lower bound for functions f : {0,1}^{n}→{0,1} on general branching programs by exhibiting a Boolean function f that requires exponential size to be computed by any branching program of length (1+ε)n, for some constant ε>0. We also give the first separation result between the syntactic and semantic read-k models for k>1 by showing that polynomial-size semantic read-twice branching programs call compute functions that require exponential size on any syntactic read-k branching program. We also show a time-space tradeoff result on the more general R-way branching program model: for any k, we give a function that requires exponential size to be computed by length kn q-way branching programs, for some q = q(k).

Original language | English (US) |
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Pages (from-to) | 254-263 |

Number of pages | 10 |

Journal | Annual Symposium on Foundations of Computer Science - Proceedings |

State | Published - Dec 1 1998 |

Externally published | Yes |

Event | Proceedings of the 1998 39th Annual Symposium on Foundations of Computer Science - Palo Alto, CA, USA Duration: Nov 8 1998 → Nov 11 1998 |

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### All Science Journal Classification (ASJC) codes

- Hardware and Architecture

### Cite this

*Annual Symposium on Foundations of Computer Science - Proceedings*, 254-263.

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*Annual Symposium on Foundations of Computer Science - Proceedings*, pp. 254-263.

**Time-space tradeoffs for branching programs.** / Beame, Paul; Saks, Michael; Thathachar, Jayram S.

Research output: Contribution to journal › Conference article

TY - JOUR

T1 - Time-space tradeoffs for branching programs

AU - Beame, Paul

AU - Saks, Michael

AU - Thathachar, Jayram S.

PY - 1998/12/1

Y1 - 1998/12/1

N2 - We obtain the first non-trivial time-space tradeoff lower bound for functions f : {0,1}n→{0,1} on general branching programs by exhibiting a Boolean function f that requires exponential size to be computed by any branching program of length (1+ε)n, for some constant ε>0. We also give the first separation result between the syntactic and semantic read-k models for k>1 by showing that polynomial-size semantic read-twice branching programs call compute functions that require exponential size on any syntactic read-k branching program. We also show a time-space tradeoff result on the more general R-way branching program model: for any k, we give a function that requires exponential size to be computed by length kn q-way branching programs, for some q = q(k).

AB - We obtain the first non-trivial time-space tradeoff lower bound for functions f : {0,1}n→{0,1} on general branching programs by exhibiting a Boolean function f that requires exponential size to be computed by any branching program of length (1+ε)n, for some constant ε>0. We also give the first separation result between the syntactic and semantic read-k models for k>1 by showing that polynomial-size semantic read-twice branching programs call compute functions that require exponential size on any syntactic read-k branching program. We also show a time-space tradeoff result on the more general R-way branching program model: for any k, we give a function that requires exponential size to be computed by length kn q-way branching programs, for some q = q(k).

UR - http://www.scopus.com/inward/record.url?scp=0032311620&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032311620&partnerID=8YFLogxK

M3 - Conference article

AN - SCOPUS:0032311620

SP - 254

EP - 263

JO - Annual Symposium on Foundations of Computer Science - Proceedings

JF - Annual Symposium on Foundations of Computer Science - Proceedings

SN - 0272-5428

ER -